According to a report in Britain's Daily Mail, the file alleges that both Moody and Malky Mackay, who was sacked as Cardiff manager by Malaysian owner Vincent Tan in December 2013, two months after right-hand man Moody was fired from his role with the club, sent a series of racist, sexist and homophobic text messages to one another during their time with the Welsh side.

A Palace statement issued Thursday said: "In light of the events of yesterday, sporting director Iain Moody has tendered his resignation and it has been accepted with immediate effect.

"There will be no further comment from the club on this matter."

Moody's departure would appear to have closed the door on Mackay succeeding Tony Pulis as manager of south London side Palace.

Mackay guided Cardiff to the Premier League after a 51-year absence from English football's top flight but that didn't stop Tan sacking both him and Moody.

Cardiff on Thursday declined to make any public comment on the dossier and the matter is now in the hands of the FA.

The FA has confirmed it has received a detailed account of issues related to Mackay and Moody.

An FA spokesman said: "The FA can confirm it is currently investigating this matter."

Caretaker Palace boss Keith Millen is now expected to take charge of Saturday's home Premier League clash with West Ham.

Other candidates to fill the vacancy at the Selhurst Park include former Norwich and Newcastle boss Chris Hughton as well as Tim Sherwood, previously in charge of Tottenham Hotspur.

After he was sacked by Cardiff, Mackay launched a �7.5million ($12.4 million, 9.4 million euros) legal claim against Tan for compensation but dropped the claim in May and apologised to the Bluebirds' owner.

Earlier this week Palace were fined by the Premier League for their part in the 'spygate' saga involving Cardiff last April.

The Premier League determined that Palace had breached their 'good faith' rule by obtaining information about Cardiff's team ahead of their 3-0 win when the two clubs were relegation rivals.

The Welsh club had complained to the Premier League that Moody had contacted Cardiff employees for information in the build-up to the game.