Atlantic Records boss Ben Cook quits after dressing up as member of hip-hop group Run DMC at a birthday party seven years ago

Photos have never emerged from the party of Mr Cook - widely regarded as one of British music's most powerful figures - and it is unknown whether he blacked up.

It is believed that his exit followed allegations about his costume circulating in the music industry, although the nature of these claims is not yet clear. 

Mr Cook, who had been at Atlantic for 12 years, said: 'It is with great sadness that today I announce I am stepping down as president of Atlantic Records, UK.

'Seven years ago, at a birthday party where guests were asked to come dressed as their favourite musical icon, I came as a member of Run DMC.

Run DMC were Jammaster Jay (Jason Mizell), Run (Joseph Simons) and DMC (Darryl McDaniels)

Mr Cook was defended today by grime MC Wiley, who worked with him on the 2008 hit Wearing My Rolex and tweeted: 'Ben Cook is not racist. Give that man back his job please'

'Late last year rumours began to circulate about my appearance at that event, many of which are simply untrue.

Mr Cook, with Charli XCX at a Warner Music Group party in London in July 2016

'While my intention was to honour a musical hero, I recognise my appearance was offensive and I made a terrible mistake.

'As a consequence of this, I readily agreed to disciplinary actions by my employer last year. Since then however, allegations surrounding the party have continued to be made against me.

'Moreover, they have been used against a wonderful company and the label I love. I have therefore come to the conclusion that I should make this statement and step down, with immediate effect.'

Mr Cook grew up in North London near Camden Town and learned to play the violin as a child.

He began his career at Ministry of Sound where he was behind the success of hits such as Call On Me by Eric Prydz and Benny Benassi's Satisfaction.

He was at Atlantic for 12 years, first working at the label's sister company Asylum Records, where he discovered Sheeran and, along with colleague Ed Howard, gave him his first record deal.

They signed Sheeran in 2011 after noting how his No. 5 Collaborations Project EP got to number two in the iTunes charts despite being an independent release. 

Mr Cook also worked with Wiley, taking Wearing My Rolex to number two, and was an instrumental force in the careers of Rudimental, Charli XCX and Anne-Marie.

Cook discovered the talent of Sheeran (pictured in January) while working at Asylum Records

During his time as president of Atlantic, the label's share of the album UK market grew to nearly 8 per cent, which was also helped by the likes of Bruno Mars and Clean Bandit. 

Mr Cook helped to bring grime star Stormzy (pictured at Transmt in Scotland in July) to the label last year as part of a joint venture with the rapper's own Merky Records outfit

Mr Cook added: 'I am devastated that this mistake has caused upset and has called into question my commitment to diversity, equality and inclusion, values which I have championed throughout my career.

'I have learned a great deal from this event and will resolutely continue to champion these values moving forward.'

Mr Cook said that it has been 'an incredible privilege to have worked with the immensely talented artists, managers and team at Atlantic and the wider Warner family'.

He added: 'I unreservedly apologise to anyone who has been hurt.'

Mr Cook was promoted to Atlantic's president in 2014. He also helped to bring grime star Stormzy to the label last year as part of a joint venture with the rapper's own Merky Records outfit.

A statement from Warner Music, the parent company of Atlantic, said: 'Ben Cook is leaving Atlantic UK and this will be his last week in the office.'

Parlophone co-president Mark Mitchell will step into the leadership role on an interim basis following Cook's departure.