Comedian Tom Arnold has vowed to release a tape of Donald Trump using the N-word and referring to one of his sons as a retard after apparently receiving a voicemail from the president-elect's team threatening to sue him.

Arnold described remarks allegedly made by the billionaire in an Apprentice outtakes reel last week. He said he would have released it before the election but did not have the approval of producers who made it and gave it to him, he said.

But the actor changed his tune on Wednesday, taking to Twitter to pledge war against Trump.

'Wife told me there's house line VM from Trump Camp about defamation suit so it's on! Open Apprentice vaults 4 discovery! Miss Universe too!!' he said.

Trump's team would not comment on Arnold's claims but an administration source told DailyMail.com there was no truth to them.

'It's on!': Tom Arnold vowed to release a tape which he claims shows Donald Trump (right in Mar-a-Lago on Wednesday) using the N word and calling one of his children a 'retard'

The comedian announced his pledge on Twitter after apparently receiving a phone call from a member of Trump's team threatening legal action

Arnold said he had approached the producers who made the tape for their approval but they were scared for their safety.

He also suggested he'd been plotting the tape's release, musing: 'Been talking/working on this 3 months but 1 random Seattle stand-up interview. Plan is working.'

The comedian also made hurried mention of 'nazis and libs' and 'taxes and Russia 2013' in his flurry of posts.

The 57-year-old made an appearance on Kiro Radio, a Seattle radio station, on Friday, during which he described the tapes in detail.

' I have the outtakes to The Apprentice where he says every bad thing ever, every offensive, racist thing ever.

Arnold suggested he had been plotting the tapes' release as he described how his 'plan is working'

Arnold said Trump was filmed making the comments while filming The Apprentice for NBC (above)

Arnold said he was contacted by both Arnold Schwarzenegger's team and aides working for Hillary Clinton who he said urged him to go public with the tape

'It was him sitting in that chair saying the N-word, saying the C-word, calling his son a retard, just being so mean to his own children,' Arnold said.

He claimed to have been given the footage, which had been packaged together and edited, by senior NBC editors and a producer.

They saw no need to release it before the election because they were certain Hillary Clinton would win, he said.

As election day approached, Arnold claims he was contacted by both Clinton's team and representatives of Arnold Schwarzenegger, the show's new host, urging him to go public.

'The Sunday before the election, I get a call from [Schwarzenegger's] CAA agent, sitting next to [Clinton]. They said, "I need you to release him saying the N-word,"' he said on the radio show.

The president-elect hosted his General Mark Flynn, his national security adviser (center) and Reince Priebus, his chief of staff, at his Mar-a-Lago mansion in Florida on Wednesday

He was also seen having discussions with chief strategist Steven Bannon inside the resort

President-elect Trump will be sworn in to office on January 20. He is spending Christmas in Florida

He refused to protect the people who gave it to him, he said.

The comedian's representatives did not respond to DailyMail.com's requests for a copy of the apparent voicemail on Wednesday. Nor did they share any more detail of who or what exactly was said.

While Arnold launched his Twitter spree on Wednesday, Trump held meetings with members of his cabinet at Mar-a-Lago where he is spending the Christmas break.

National Security Adviser Lt. General Michael Flynn, his Chief of Staff Reince Priebus and chief strategist Steve Bannon were all present for the talks.