A leading Canadian expert on privacy rights says it's "troubling" a Halifax Regional Police officer would allegedly delete a video showing officers making an arrest.

But David Fraser said he's also relieved authorities appear to be taking the allegations seriously.

The incident was referred to Nova Scotia's Serious Incident Response Team in November. A lawyer contacted SIRT on behalf of a 17-year-old boy who was arrested the previous June in Dartmouth.

According to SIRT, the teen said one of the officers deleted a video showing the arrest, shot by another person on their phone.

"One thing we need to bear in mind: police officers have no privacy rights when it comes to carrying out their official functions," Fraser said. "And so sometimes they will assert privacy rights and it's completely bogus."

Fraser is a partner with the Halifax law firm McInnes Cooper and blogs about privacy. He said the incident described by SIRT appears to run contrary to what is allowed.

"It's incredibly troubling when you have a citizen who has taken a video of a police officer doing his or her functions and then the police officer then deletes it, which obviously raises the question of what was that police officer trying to hide in those circumstances," he said.

Fraser said people are not obliged to hand over their phones, unless there is an active criminal investigation underway. Even then, he said there are limits on what police can do and there is no obligation for people in most circumstances to unlock their phones.

Fraser said he finds the case SIRT is investigating troubling because the complainant is a minor and likely to be more susceptible to coercion by police.

Fraser said if the SIRT investigation supports the allegation, this may not just be a case of obstruction. He said if the officer did delete a video, it could violate hacking statutes that prohibit the altering or deleting of data.