Three Imams accused of glorifying a murderer during sermons at High Wycombe mosques will be called to give evidence in front of a retired judge as part of a hate-preaching investigation.

An independent investigation is set to start in the coming days after a Muslim man accused the religious figures of likening a Pakistani murderer to a “martyr” in front of hundreds of worshippers earlier this year.

Having received a complaint from whistleblower Khalil Ahmed in March, the Wycombe Islamic Mission and Trust has appointed former judge Khurshid Drabu CBE to lead the probe.

Trust secretary, Shafait Ali, said: “We realise that these are very serious allegations and it was important we got someone who could be independent, open, fair and transparent.

“It is important that Mr Khalil Ahmed’s concerns are looked into fully.

“He [Mr Drabu] will be able to speak to who he wants to and we will do what we can to help the investigation.”

Bosses of the Jubilee Road Mosque, Townfield Mosque and Castlefield Mosque say they are taking the allegations “very seriously” and had started an internal investigation following emergency meetings.

They have since decided to call for an independent party to review all of the evidence regarding the comments which the Imams are alleged to have said.

The three Imams, Sultan Mehmood, Hafiz Hamid Uddin and Ghulam Jeelani, have all represented High Wycombe for more than 10 years, with the latter being in his position at Jubilee Road for more than 30 years.

Mr Ahmed, from Micklefield, claims the trio led a prayer earlier this year for a bodyguard who assassinated the Pakistani governor he was hired to protect because of the politician’s opposition to blasphemy laws.

The killing – which led to the execution of murderer Mumtaz Qadri – resulted in dispute across the world. And Mr Ahmed previously condemned the Imams for “taking sides” and “glorifying the terrorist”.

The Wycombe Islamic Mission and Trust, which controls the three mosques under scrutiny, has said it will not stand for such behaviour.

Bosses added they will take any action necessary following the conclusion of the investigation.

Mr Ali added: “The board of directors of Wycombe Islamic Mission and Mosque Trust Ltd sought a legal advice regarding Mr Khalil Ahmed’s complaint about the Imams sermons on March 4 and 11, 2016, and decided to carry out an independent investigation.

“Following Eid we will arrange a timetable for the investigation.

“It should be concluded in 10 days.

“The independent investigator believes this will be enough time to review all the information and come to a conclusion.”

Mr Drabu was previously a retired senior immigration judge at the Asylum and Immigration Tribunal and a legal member at the Special Immigration Appeals Commission.

Prior to that he held a senior position with the Immigration Advisory Service and Commission for Racial Equality.