The relationship between the suicide bomber who killed 22 at a concert in Manchester, England and the mosque he attended is coming under fresh scrutiny after recordings emerged of an apparently extremist sermon preached just months before the attack.

The words of the sermon, which have been analysed by Islamic scholars and are being investigated by police, amount to a call to violence according to British state broadcaster the BBC, which quotes the remarks of experts Usama Hasan and Shaykh Rehan who said the preaching called for “military jihad”.

Salman Abedi / AP IMAGES

In the recording, Imam Mustafa Graf is alleged to pray “We ask Allah to grant them mujahideen [Islamist fighters] – our brothers and sisters right now in Aleppo and Syria and Iraq – to grant them victory”, and to claim “Jihad for the sake of Allah is the source of pride and dignity for this nation.”

In an apparent call to action, the Imam also said: “brothers and sisters, it is time to act. Not only to talk.”

Usama Hasan of the anti-extremism think tank the Quilliam Foundation told the broadcaster about the comments by Imam Mustafa Graf that: “From the context and the way these texts are used they are clearly referring to military jihad, to armed jihad.

“I have known the Islamic discourse for pretty much 40 years… and the mujahideen are the group fighting armed jihad.”

Shaykh Rehan said of the speech: “He’s giving them the narrative of them against us. He is psychologically and practically brainwashing young people into either travelling or to do something to take action.”

The mosque itself, housed in a former Victorian church, has denied extremism is preached within its doors, and told the BBC that words used like “mujahideen” and “jihad” had merely been misinterpreted. Greater Manchester Police are reviewing the new material to determine whether an offence has been committed.

Imam Graf also denied on camera preaching hate speech — footage that the BBC contrasted with archive footage of him in 2011, wearing military uniform in Libya, talking to camera about “awaiting orders to attack” while men around him loaded ammunition into an armoured fighting vehicle.

The BBC report also claimed five men who attended the mosque have either travelled to Syria or been jailed for serving the Islamic State, a further claim that the mosque denies. The Guardian reports the Mosque said in a statement that: “We do not tolerate or instigate any form of preaching that breaches both Islamic principles and the laws of England and Wales.”

It is not known whether Abedi and his family, who were frequent worshippers at the Mosque, were present when the sermon was delivered. However, Abedi bought a ticket for the Ariana Grande concert where he detonated a suicide bomb the following year just ten days after the sermon was given.

Salman Abedi, the Manchester Arena bomber was 22-years-old at the time he detonated a home-made explosive device loaded with shrapnel in the foyer as an Ariana Grande concert finished, killing 22 parents and children leaving the event, and himself. British born to Libyan parents, a British Royal Navy ship had “rescued” Abedi from the Libyan civil war in 2014 where it is alleged he had been engaged in militant activity.

The victims of Abedi’s attack included ten peopel under the age of 20, the youngest being just eight years old. Over 800 were injured “physically or psychologically” in addition to the dead, with many receiving life-changing wounds.