Newham College has been included in a list of “gay-friendly” employers, despite its head of performing arts being sacked last month for a homophobic rant.

Gay rights group Stonewall defended the decision to keep the college on its Top 100 Workplace Equality Index 2014, calling the teacher’s remarks an “isolated incident”.

Mark Walcott was fired in December after a recording from 2012 of him making homophobic remarks was posted online by staff members who felt a year-long inquiry by the college into the speech had gone nowhere.

The college’s principal, Denise Brown, who headed the inquiry, stepped down a week later.

Simon Feeke, Stonewall’s head of workplace programmes, appearing on ITV news last night, said: “Newham College have consistently been one of the top performers in the [further education] sector for their work force specifically.

“They have a really well established staff network which really works to enhance the visibility of gay people within the organisation and really change the culture, and they have a really strong commitment right from the top.”

When asked about Mr Walcott’s homophobic rant, Mr Feeke said: “That was an isolated incident, a very, very unfortunate incident, and we’ve been working closely with Newham College since it was brought to light.

“Thankfully the correct procedure was followed and actually the appropriate action was taken.”

He added: “Newham College over the years has done so much to really build a robust framework that actually, within time, and with our support, they were able to see that it was an isolated incident, and it has been dealt with.

“I think there are occasions where there are similar situations that don’t get dealt with as swiftly.”

In the 50 minute recording, posted online in November 2013, Mr Walcott is heard to say: “Boys are becoming gay not because they have a gay gene but because they have gay teachers who are indoctrinating them with their gay mentality.”

He is also heard claiming he has asked gay teachers to leave schools, and that their sexuality can stop them doing their jobs properly.