Five opposition figures charged over unauthorised assemblies in Hong Kong last year have obtained a temporary court order to prevent police from accessing their phones.

The High Court issued the order on Saturday following an emergency hearing requested by lawyers for veteran pan-democrat Martin Lee Chu-ming and four others, Albert Ho Chun-yan, Au Nok-hin, Sin Chung-kai and Yeung Sum, who filed a judicial challenge earlier in the morning.

They took issue with the wide power granted to the force in a warrant late last month and argued police were still trying to search their phones even though they would have completed their investigation.

The five, all former Democratic Party lawmakers, are among a group of 15 people facing a total of 61 charges in relation to processions that took place on August 18, August 31, October 1 and October 20.

The charges include organising an unauthorised assembly, knowingly taking part in an unauthorised assembly, and incitement to knowingly take part in an unauthorised assembly.

The 15 appeared at West Kowloon Court on June 15 and had already been told their cases would be transferred to the higher District Court.

But on June 26, police informed lawyers for the five they had obtained a warrant to access their phones, which would be executed as soon as July 3.

In the High Court on Saturday, Robert Pang Yiu-hung SC questioned why police had applied for the order to search his clients’ phones even though their investigation would have been completed.

That was demonstrated by the fact prosecutors had already applied to move the case to a higher court, he argued, challenging the warrant’s necessity and reasonableness.

Pang also said the warrant police had obtained was so wide that it failed to state what information they were allowed to access, as well as how long the search would last. He asked for an injunction order to stop police from searching the phones.

Mr Justice Russell Coleman granted a temporary injunction order and convened a further hearing on July 10 for police and lawyers for the five to argue whether the order should continue.