Leaflets calling for the killing of members of the Ahmadi sect of Islam have been found in a south London mosque.
A pile of the flyers, which were found in Stockwell Green Mosque, seem to endorse the killing of Ahmadis if they do not convert to mainstream Islam.
It has been speculated that they were printed by Khatme Naubwwat - a group which says on its official website that its “sole aim has been and is to unite all the Muslims of the world to safeguard the sanctity of Prophethood and the finality of Prophethood and to refute the repudiators of the belief in the finality of Prophethood of the Holy Prophet Hazrat Muhammad”.
The leaflets say Ahmadis must convert to mainstream Islam within three days or face "the capital punishment”, meaning death.
They said they were written by Yusuf Ludhianvi, the founder of Khatme Naubwwat in Pakistan, who died in 2000.
One of the mosque’s trustees, Toaha Qureshi, said he had never seen the leaflets before and suggested they were fakes left there “maliciously”.
He told the BBC: "We have not published any pamphlet of that kind. This is nothing to do with our mosque. Someone might have put it there and taken from there with malicious intentions".
He also distanced himself from Khatme Naubwwat, saying the link between it and the mosque is only for “when we need some guidance or literature on that particular issue”.
Despite this, Mr Qureshi is listed as one of the trustees of the organisation and the mosque is listed as its UK headquarters in accounts filed to the Charity Commission for the financial year 2012-13.
The discovery of the leaflets follows the murder of a Glaswegian Ahmadi shopkeeper, Asad Shah, outside his shop on 24 March.
In a bizarre statement issued through his lawyer last week, the man accused of Mr Shah's murder, fellow Muslim Tanveer Ahmed, admitted to killing him because he “disrespected Islam”.
The is no suggestion that Khatme Naubwwat was involved in Mr Shah's killing.
The Ahmadi branch of Islam was founded in 1889, by Mirza Ghulam Ahmad in India.
Ahmadis believe Ahmad - who died in 1908 - was a prophet.
This is regarded by many mainstream Muslims as heretical as the Prophet Muhamed is supposed to be the last Islamic prophet.
Pakistan became the first and only country in the world to forbid Ahmadis from calling themselves Muslims following a constitutional amendment in 1974.
The Khatme Naubwwat movement has been linked to several hate crimes against Ahmadis in Pakistan and in 2010 The Independent revealed that the organisation had been accused of handing out leaflets calling for violence against them in Kingston-upon-Thames.
A page on their website, called "Funeral of Qadyanies", says: "It is forbidden for a Muslim to treat the Mirzai apostates like Muslims. It is unlawful, totally unlawful, to associate with them, eat and drink with them and participate in their joys and sorrows or to invite them to one's own joys and sorrows.
"Those who show such kind of toleration invite the wrath of Allah and the Prophet and it does not befit a believer to maintain friendly relations with the enemies of Allah and the Rasool."
Akber Choudhry, a spokesman for the Qern academy which runs the unaffliated Khatm-e-Naubwwat Academy in east London said they do not condone violence.
He said: "We do not propose, encourage or condone any violence by any person against any other person in any state. Part of our shared humanity and civilization is the founding principle of the state: that violence or punishment is the sole prerogative of the state, and citizens of an established state give up the right to take the law into their own hands. Anything else would be anarchy."
The Independent has contacted Mr Qureshi for comment.