Malky Mackay is no longer in contention to succeed Tony Pulis as Crystal Palace boss amid misconduct allegations from his former club Cardiff City.
The Welsh club claim he sent texts of a racist, sexist and homophobic nature while employed by them, according to the Daily Mail.
Cardiff have sent a dossier to the Football Association outlining their allegations against the Scot.
Mackay, 42, had been the favourite to take over at Selhurst Park.
An announcement confirming his appointment - to his first role since being sacked by Cardiff in December - had been widely expected before the weekend.
Cardiff also allege wrongdoing by Palace's sporting director Iain Moody, Cardiff's head of recruitment under Mackay before being sacked in October.
Moody resigned from his role on Thursday morning.
The FA has confirmed it has received a detailed account of issues related to the pair's time at Cardiff.
A spokesman added: "The FA can confirm it is currently investigating this matter."
In May, Mackay and Moody apologised to Bluebirds owner Vincent Tan over the issues that led to their dismissals and halted legal action against the club after agreeing settlements.
Beyond confirming Moody's departure, Palace have not commented on the latest claims. Cardiff, Mackay and Moody have kept their counsel, too.
Cardiff made the allegations to the FA two weeks ago and were asked to provide evidence, which they have now done.
However, the FA has previously declined to act over what it considers to be private correspondence. Premier League chief executive Richard Scudamore escaped censure earlier this year following newspaper revelations he had exchanged offensive emails with colleagues.
FA chairman Greg Dyke said at the time: "The FA does not as a matter of policy consider private communications sent with a legitimate expectation of privacy to amount to professional misconduct."
Meanwhile, Cardiff have given Palace and Moody notice they intend to serve legal action against them for their involvement in last season's so-called 'spygate' incident.
The Eagles beat Cardiff 3-0 in April only for the Welsh side to complain that their starting line-up had been leaked to their London rivals. Palace and Moody denied any wrongdoing.
Former Tottenham boss Tim Sherwood, 45, is now favourite for the Palace job.
Like Mackay, Sherwood has been interviewed for the post following Pulis's departure.
Caretaker-manager Keith Millen is also interested in taking the job full-time.
He took charge for Saturday's 2-1 defeat at Arsenal, which came just 48 hours after Pulis left the club.
"I know I can manage. I want to speak to the chairman and see which direction he wants to go in. If he has got belief in me, I will speak to him," Millen said.
|Sherwood's record at Tottenham|
|Played: 28||Won: 14|
|Drawn: 4||Lost: 10|
Sherwood would like to install the assistants he had during his time at Spurs - Les Ferdinand and Chris Ramsey - on the coaching staff.
The ex-Tottenham midfielder took over at White Hart Lane following the sacking of Andre Villas-Boas in December last year.
Sherwood himself was sacked in May 2014 after finishing sixth in the Premier League.