The chief executive of a Muslim charity has stepped down as new concerns were raised about the organisation's alleged links to extremism.

Rizwan Hussain has stepped down from the east London-based Global Aid Trust (GAT) education charity, ahead of the broadcast of an undercover TV investigation which looked into whether the organisation was promoting extremism.

The Charity Commission, which has already opened a case against the GAT, has been told of footage obtained by ITV's Exposure: Charities Behaving Badly documentary. It found an invited speaker at a GAT event seeming to make anti-Semitic remarks and offer jihadists his blessing.

A Charity Commission spokesman said they were "already aware that there were concerns of a similar nature" regarding "allegations of links to extremism" against the GAT.

He said the new evidence will be added to its current case, noting: "The claim is that they had invited external speakers to events without doing proper checks on the individuals or as to what they would be saying at the event.

"Certainly the film evidence is of someone who has been invited to an event and it is clear that a young lad has no steer about what he should be checking or asking of that person."

Rizwan Hussain, who is also a television presenter for the Islam Channel and a barrister, told Third Sector magazine that he had left the charity "in connection with the documentary".

GAT describes itself as an independent charity which aims to promote education among the underprivileged and to help orphans achieve their full potential.

The Charity Commission said it had visited and inspected GAT's premises in November 2014 after "concerns" were identified regarding one of GAT's events in May 2014.

In the programme the undercover reporter, posing as a volunteer, is introduced to a GAT worker called Shaffiq Shabbar who tells him of his admiration for the late hate preacher Anwar al-Awlaki, who was believed to have inspired a string of terror attacks.

Mr Shabbar tells the reporter: "They spread loads of lies about him...He's a scholar and basically he was imprisoned and after he came out of prison he started to incite hatred and telling the Western Muslims to bomb.

"He incited bombings basically. Bruv, he was a brilliant guy though."

The documentary also shows preacher Dawah Man speaking at an event in which he makes a series of anti-Semitic comments, telling those gathered: "America, European countries, whatever you call it, these countries are controlled by Zionists.

"If you look at the biggest bankers in the world, that fund these countries, they are Zionists, and Zionists run Israel. So we can safely say that at any time there was an American, or English or whatever, invasion of the Muslim lands, it is all a problem coming back to the Children of Israel."

In the programme GAT said it "firmly condemns and reject comments" made by Mr Shabbar and the external speakers.

It adds: "We express our great regret at these incidents, which were the result of a process failure in the organisation."

It confirms that Mr Hussain left GAT in December 2014.

They claimed that a due diligence form regarding the content of what the speaker might say was not provided when he was booked and that the staff member responsible was suspended and later resigned.

ITV's Exposure: Charities Behaving Badly is on ITV at 10.40pm on Wednesday.