Donald Trump's personal attorney Michael Cohen will plead the Fifth Amendment to avoid self-incrimination in a law suit brought by Stormy Daniels, a court was told Wednesday.

Cohen, whose business dealings are under FBI investigation and whose office, home, hotel room and safe deposit box were raided this month, will make the plea in a California civil case.

It means that he believes he could incriminate himself when giving evidence in the case - a move which will raise fears in the Trump camp over what crimes he may think he could be charged with.

The development was disclosed in a brief court filing in Los Angeles.

Cohen and Trump are both being sued there by Daniels, real name Stephanie Clifford, to try to end the $130,000 gag order she agreed to before the election, which stopped her speaking about her claim of sex with the then candidate.

Daniels' attorney, Michael Avenatti, said on Twitter that it was 'a stunning development' because it was a case involving 'issues surrounding the President'.

He added a link to a report that quote Trump as saying in 1990: 'If you're innocent, why are taking the Fifth?'

What does he know? Michael Cohen is pleading the Fifth Amendment to avoid incriminating himself when he takes part in a civil case brought by Stormy Daniels

Key development: Michael Cohen has told a court in California that he will take the Fifth Amendment in civil litigation brought by Stormy Daniels - meaning that he could incriminate himself through evidence in the case

Predicted move: Michael Avenatti, Stormy Daniels' attorney, said earlier this month that he believed Cohen would take the Fifth Amendment

During an appearance on CNN on Wednesday night, Avenatti said he predicts that the Cohen investigation will result in Trump's resignation

During an appearance on CNN on Wednesday night, Avenatti said he predicts that the Cohen investigation will result in Trump's resignation.

Avenatti said he believes the government has evidence that Cohen was in touch until recently with Keith Davidson, the former attorney for Daniels who negotiated the $130,000 non-disclosure agreement.

‘There’s substantial reason to believe that these two attorneys were continuing to communicate with one another well into this year about my client, the settlement, the negotiation, and documents relating to this payment,' Avenatti told CNN.

Cohen told the judge: 'Based upon the advice of counsel, I will assert my 5th amendment rights in connection with all proceedings in this case due to the ongoing criminal investigation by the FBI and U.S. Attorney for the Southern District of New York.

'On April 10, 2018, I first realized that my Fifth Amendment Rights would be implicated in this case, after I considered the events of April 9, 2018.'

The move was predicted earlier this month by Daniels' attorney Michael Avenatti.

After the filing, he tweeted: 'This is a stunning development. Never before in our nation's history has the attorney for the sitting President invoked the 5th Amend in connection with issues surrounding the President. It is esp. stunning seeing as MC served as the 'fixer' for Mr. Trump for over 10 yrs.'

It will be seen by the president's defenders as a worrying indication that Cohen has committed a crime in some form - which could then be used by Robert Mueller, the special counsel, to turn on Trump in return for immunity.

Trump has ridiculed the idea that Cohen would 'flip', but taking the Fifth in the civil case is a sign of the attorney's growing fear that he could face charges.

One person who has taken the threat of Cohen flipping seriously is his former legal adviser, Jay Goldberg.

Jay Goldberg, Trump's former legal adviser, told the president recently that it is virtually certain Cohen will 'flip' if he is indicted by the federal government

Goldberg told The Wall Street Journal earlier this month that it is virtually certain that Cohen will cooperate with federal investigators and turn over damaging information about Trump if he is faced with criminal charges.

Goldberg, who represented Trump in the 1990s and early 2000s, said he spoke with the president recently and warned him that Cohen would turn on him if it meant staying out of prison.

Goldberg said he told Trump that on a scale of 100 to 1, where 100 is fully protecting the president, Cohen ‘isn’t even a 1.’

The FBI raid was ordered by federal prosecutors in Manhattan after information was passed to them by Mueller. The nature of Mueller's tip-off has not been disclosed.

Cohen asked the judge to delay the civil case after his office and residence were raided by the FBI.

At a hearing last week, U.S. District Judge James Otero said he needed more time to review the request for a stay, but he told Cohen's attorney 'there's some gaping holes' in the request.

Daniels has been seeking to invalidate the nondisclosure agreement she signed days before the 2016 elections so she can discuss the alleged relationship - which Trump denies - without facing penalties.

She argues it invalid because Cohen signed it, but the president did not.

That did not stop her from describing her sex with Trump to Anderson Cooper on CNN, but her legal team say that she could be sued for doing so and want that threat lifted.

The development came as former New York City Mayor Rudy Giuliani – the newest member of Trump's Russia-probe-focused legal team – sat down with Special Counsel Robert Mueller on Tuesday.

Former New York City Mayor Rudy Giuliani (left), who is now representing President Trump in the Russia probe, sat down with Special Counsel Robert Mueller (right) on Tuesday

The Washington Post reported that Giuliani reopened discussions on a potential interview between Trump and Mueller, conversations that had broken down in the aftermath of the FBI's raid on longtime Trump lawyer Michael Cohen's office, hotel room and home.

The ex-mayor, the Post noted, told Mueller that there was still great reluctance in agreeing to an interview, but did not rule it out.

Giuliani also asked Mueller when the Russia probe might be done, the newspaper's sources said.

Mueller, in turn, told Giuliani that he wished to ask the president about the decisions he made during the transition and early months of the administration.

It is important for investigators to understand the president's intent as they look into potential obstruction of justice, Mueller noted.

Mueller, the head of the FBI before James Comey, and Giuliani, who stewarded New York City through the 9/11 terror attacks, have known each other for years thanks to their law enforcement backgrounds.

Last week upon his hiring to Trump's legal team, Giuliani suggested he would be the individual to get the Russia probe resolved.

'I'm doing it because I hope we can negotiate an end to this for the good of the country and because I have high regard for the president and for Bob Mueller,' the ex-mayor had told the Washington Post last week.

Trump has vehemently and repeatedly denied collusion with Russia, calling it a 'witch hunt' and also slammed claims that Cohen would flip on him because he had not been treated well by the president.

He dismissed them as based on a 'drunk/drugged up loser', although officials would not say who that was.

One report in the New York Times which appeared to have caused Trump's ire mentioned both Roger Cohen, his long-time adviser, and Sam Nunberg, a former Trump adviser who went into rehab e after a series of television interviews on which he claimed he would not co-operate with Mueller.

In a string of tweets on Saturday morning, President Trump defended Michael Cohen and said he did not think he would 'flip' on him as has been suggested. He deleted the tweets then reposted them shortly afterwards with the correct spelling of Maggie Haberman's name. Haberman published a report on Friday citing multiple unnamed sources who said it was a possibility that Cohen might turn on Trump