A former campaign aide to US president Donald Trump said on Monday he would not comply with a subpoena to testify before a grand jury in special counsel Robert Mueller’s investigation into Russian meddling in the 2016 US election.

Sam Nunberg first worked for one of Mr Trump’s businesses and later helped advise Mr Trump’s presidential campaign, but he was fired in August 2015 amid reports that he posted racially charged messages on Facebook.

In multiple interviews with media outlets on Monday, Mr Nunberg said he would refuse to comply with the subpoena. If he does not comply, he would risk serving time in jail.

“I’m not going to cooperate,” Mr Nunberg told MSNBC.

“Let’s see what Mr Mueller does. I think it would be funny if they arrested me. I think it would be really, really funny if they wanted to arrest me because I don’t want to spend 80 hours going over emails I had with Steve Bannon and Roger Stone,” he said, referring to both the former White House chief strategist and one of Mr Trump’s associates.

He later told AP, however, he would end up cooperating with the investigation, and that he would be more willing to comply with the subpoena if its scope was narrowed.

Robert Mueller’s investigation arose in part from the findings of US intelligence agencies that Russia had meddled in the election and that its goals eventually included aiding Mr Trump, who won a surprise victory over Democrat Hillary Clinton. Russia has denied the allegations and Mr Trump has said there was no collusion between Moscow and his campaign.

Mr Mueller has charged several of Mr Trump’s associates and more than a dozen Russians.

In a telephone call with MSNBC, Mr Nunberg said a subpoena to appear before a grand jury was “absolutely ridiculous.” He rejected any notion that Mr Trump had colluded with Russians.

“Donald Trump did not collude with the Russians. It is the biggest joke to ever think that Donald Trump colluded with the Russians,” said Mr Nunberg.

A person who refuses to testify or produce documents can be jailed for up to 18 months for civil contempt. The person could later be charged with criminal contempt, said Barbara McQuade, a former US Attorney for the Eastern District of Michigan who teaches law at the University of Michigan.

“It is incredibly dangerous and it’s also such a bad idea to do it so publicly,” she said of Mr Nunberg’s public pronouncements.

The only ways to avoid a grand jury subpoena are invoking the Constitutional right to avoid self-incrimination or claiming attorney-client or executive privilege, but these are not always successful.

Last year, Mr Mueller’s office won a court order forcing a lawyer for former Trump campaign manager Paul Manafort to testify before the grand jury after she claimed attorney-client privilege.

“When a person uses the attorney-client relationship to further a criminal scheme, the law is well established that a claim of attorney-client ... privilege must yield to the grand jury’s investigatory needs,” Chief Judge Beryl Howell wrote on October 2nd, 2017. – Reuters