Police said on Friday that investigative and testimonial material in criminal cases is lawfully passed to the parties involved, as they responded to a complaint from Akel General Secretary Stefanos Stefanou over a football fan’s video showing what appeared to be witness statements.

The video was published by an Apoel supporters’ fan page on social media and has since been taken down; it showed original statements, complete with signatures and other markings, as well as a medical report.

Stefanou says such papers should be held only by police or the legal service.

In a letter to police chief Themistos Arnaoutis on Thursday, Stefanou asked for an investigation and for an explanation of how police documents came to be in the hands of third parties.

He also questioned how the force manages documents containing depositions and medical reports.

Police spokesman Vyron Vyronos said the origin of the material is under investigation and that it is premature to speak of a leak.

Speaking on CyBC, Vyronos urged caution, saying “it is not right to talk about a leak without having a clear picture of the situation”.

He explained that in criminal cases the material is provided to those involved so they can prepare a defence in court.

Vyronos said police could not yet confirm whether the documents were confidential or whether they were witness material already given to the parties.

He said investigators were still trying to establish where the papers came from, and which case, if any, they related to.

He said the fragments seen online resembled material received by parties for representation in court.

Asked in regard to the appearance of original medical documents and statements, Vyronos said the same rule applied once a case is registered in court, that being that witness material, whether testimonies or reports, goes to the defence.

Pressed on whether police were checking if the documents were held only by the authorities or had also reached others, he said “everything is being investigated”.

The data protection commission informed the House recently that fines had been imposed on the police for leaks of confidential information or depositions, in breach of the law.

The video appeared as tension grew between supporters of Omonia and Apoel ahead of the derby at the GSP stadium on Sunday.

Since Tuesday, fan groups linked to Gate 9, the Omonia ultras fan club, have posted ahead of the match, some accusing rivals of making complaints to police.

A fan page associated with Apoel supporters then responded with the video.

Both sides have announced marches in Nicosia before kick-off, with Gate 9 calling on supporters to gather at Archermou from 11am and march to the stadium, while Apoel ultras fan AU79 has invited its members to its own march.