In Commissioner of Police v Barbaro  QCA 230 Sofronoff P and Philippides and Mullins JJA have found, in the specific circumstances, that an assertion that some communications on a mobile phone are protected by legal privilege constitutes a reasonable excuse not to comply with a search warrant requiring the subject to give the PIN to police.
The judgment states
 On 22 May 2018 police obtained a warrant from a magistrate to search certain premises on the Gold Coast. The warrant asserted the commission of certain offences by the respondent authorised a police officer to “seize a thing found at the relevant place ... that the police officer reasonably suspects may be warrant evidence or property to which the warrant relates”, which included “mobile phones”. The warrant also expressly required the specified person to allow a police officer to “examine the stored information to find out whether it may be evidence of the commission of an offence” and to copy such information.
 Section 154(1) of the Police Powers and Responsibilities Act 2000 (Qld) provides that a magistrate who issues a search warrant may order a “specified person” to “give a police officer access to ... the access information ... necessary for the police officer to be able to use the storage device to gain access to stored information that is accessible only by using the access information”. Section 150AA of the Act defines the term “storage device” to include a “device on which information may be stored electronically”. A mobile phone is such a device. The same section defines “access information” to mean information that is necessary for a person to access and read information stored electronically on a storage device. That definition applies to a password that permits access to the content of a mobile phone. Section 156(3) of the Act provides that a warrant that contains an order to furnish access information must state that a failure, without reasonable excuse, to comply with the order may be dealt with under s 205A of the Criminal Code (Qld). That provision of the Code makes it an offence for a person to contravene an order made under s 154(1) of the Act.
 The two parts of the warrant, namely the express order to give access information and the warning that a failure to give the information without a reasonable excuse may result in a charge being laid alleging the commission of an offence against s 205A of the Code, have to be read together. The result of such a reading is that the order is one which requires a person to furnish access information unless the person has a reasonable excuse to refuse to do so.
 Police executed the warrant at the relevant premises on 24 May 2018 and found a mobile phone that belonged to the respondent. A police officer ordered the respondent to reveal the PIN that would unlock it. It is common ground that the respondent was a “specified person” to whom such an order could be given and that the respondent was obliged to give the information unless he had a reasonable excuse for refusing and that, if he refused without a reasonable excuse, he would be guilty of an offence under s 205A of the Code. The respondent refused to give the information and, accordingly, he was charged.
 At the trial in the Magistrates Court, the prosecution led evidence to prove the facts set out above, none of which was disputed. The respondent gave evidence. He said that the reason he had refused to reveal the password was that he had been in the habit of using the phone to communicate with his solicitor by using various text messaging systems on his phone. The phone contained numerous privileged written communications between the respondent and his solicitor and he did not wish police to read these messages. This evidence was not challenged. The respondent claimed at his trial that his right to protect privileged information constituted a reasonable excuse for his refusal. For reasons that it is unnecessary to detail, the learned Magistrate rejected this defence and found the respondent guilty.
 The respondent appealed to the District Court and Kent QC DCJ upheld his appeal. In substance the respondent submitted, and Kent QC DCJ accepted, that he was entitled to maintain his privilege against disclosure of certain of the information even if other information contained on the phone was not privileged and this claim constituted a reasonable excuse for his refusal. His Honour set aside the conviction.
 The Commissioner of Police has applied for leave to appeal against that decision. She submitted that leave to appeal should be granted because the appeal would raise an important question of law. That submission should be accepted and leave to appeal should be granted.
 As the appellant has framed her case, the question in this appeal is whether, as a matter of law, the respondent’s asserted reason for refusing to give up his password was capable of constituting a reasonable excuse. The Commissioner submitted that Kent QC DCJ failed to take into account that legal professional privilege could not have attached to all the information stored on the phone. In her written submissions, the Commissioner submitted that unless the respondent was able to claim that all of the information on the phone was privileged, “the dominant purpose test cannot be satisfied and the privilege cannot be relied on to prevent a compulsory process for the obtaining of evidence” (italics in the original). The Commissioner pointed out, correctly, that the respondent’s claim did not go so far as to assert that all the information on the phone was privileged nor did his evidence identify the documents over which he claimed privilege. ... It was submitted that because privilege could not attach to all of the documents on the phone it followed that a claim of privilege could not be relied upon as a reasonable excuse to refuse to disclose the password.
The QCA did not accept those submissions, stating
 It has been established that legal professional privilege is a rule of substantive law which may be availed of by a person to resist the giving of information or the production of documents which would reveal communications between a client and his or her lawyer made for the dominant purpose of giving or obtaining legal advice. The right to refuse to disclose information extends to a right to resist giving information required by a search warrant.
 Three things can be said about the expression “reasonable excuse”. First, the word “reasonable” connotes that the excuse must be objectively reasonable. Second, whether something is “reasonable” will depend not only upon the particular facts of the case but also upon the statutory context in which the word appears. Third, although it need not be the only reason, the asserted reasonable excuse must actually be a person’s reason for withholding the access information.
 In this case the word appears in a search warrant pursuant to which police were endeavouring to obtain evidence, including in the form of written information, that might tend to prove the commission of offences by the respondent. The mobile phone in this case was one of the kinds of things expressly referred to in the warrant as a “storage device” that might contain “stored information” and the warrant expressly empowered a police officer to look at that information “to find out whether it may be evidence of the commission of an offence”. In this way, the service of the warrant upon the respondent, the seizure of his phone and the demand for the password that would unlock the phone constituted an unmistakeable assertion by police that they intended to read the information contained on the phone including any privileged information as soon as that was practicable. ...
 In this case the demand made of the respondent to reveal the password that would unlock his phone was made in terms that did not suggest that police accepted any limitation upon their powers of inspection of documents that they found on the phone. Police were asserting a right to read every document on the phone.
 The context in which the words “reasonable excuse” appear in this case is of significance to the result of the appeal. The words appear in the warrant because a statute required that they be used to qualify the otherwise absolute terms of the obligation of disclosure that the warrant imposed upon the respondent. This search warrant was part of the investigative pre-trial process of the criminal law, the function of which is to authorise the seizure of material that will implicate a person in the commission of an offence. This is a process that is intended to yield evidence which can be tendered by the prosecution to obtain a conviction. Undoubtedly, some of the best evidence of that kind might well be found in what an alleged offender has confided to a lawyer. Yet such material is held to be immune from disclosure because the ability of a client to confide freely in a lawyer is regarded by the law as indispensable to the functioning of our legal system. It is in the public interest that candid communications be permitted between lawyers and their clients and it is for this reason that privileged communications are protected against disclosure. Indeed, so important is this principle that the improper disclosure of communications that are the subject of privilege might even result in criminal proceedings being stayed.
 The appellant’s submissions, that the respondent did not go so far as to claim that every piece of information on the phone was privileged, thereby failing to satisfy the dominant purpose test, and that the respondent failed to identify the privileged documents, are beside the point.
 The dominant purpose test established by Esso Australia Resources Ltd v Federal Commissioner of Taxation is concerned with the question whether legal professional privilege attaches or does not attach to a particular piece of information. It is irrelevant to this case because the existence of privilege over at least some of the documents on the phone has been accepted. ....
 In this case, for the reasons given, the respondent was faced with an apparent demand by police for access to the contents of his phone, which, so far as one could tell by their actions, the police officers intended to read as soon as was practicable. Disclosure of the password would have meant putting police officers in an immediate position to read the privileged information. The only way to protect the confidentiality of the privileged information was for the respondent to deny access to the phone. The warrant was sufficient authority for police to take the phone away in order to preserve any evidence that might be on the phone so there was no risk that evidence might be lost. There were no extraneous factors that might have rendered his refusal, at that time, unreasonable.
 That is not to say that the result will always be the same when police require access information to enable them to examine the contents of a mobile phone. It will not always be a reasonable excuse to refuse to disclose access information just because the phone contains privileged information. Everything will depend upon the circumstances. Police remain free to seize a phone, provided the warrant authorises such seizure, and the presence of privileged information on a phone may cease to constitute a reasonable excuse if circumstances change, such as the making of adequate arrangements to ensure that their search of the phone is done in a way that does not involve breaching privilege. In any case, it will be for the person claiming the excuse to establish the claim for privilege if the claim is contested. The respondent did so here.