Donald Trump's former national security adviser has reportedly offered to testify at hearings into alleged Russian meddling in the US election in exchange for immunity.

Michael Flynn's lawyer said the retired lieutenant general "certainly has a story to tell and he very much wants to tell it, should the circumstances permit."

He insisted his client had been the victim of "unfounded allegations, outrageous claims of treason, and vicious innuendo directed against him".

He added: "No reasonable person, who has the benefit of advice from counsel, would submit to questioning in such a highly politicised, witch hunt environment without assurances against unfair prosecution."

Mr Flynn was fired by Mr Trump after intelligence leaked to journalists showed public assurances made by Vice President Mike Pence that he had not discussed sanctions with the Russian ambassador were false.

The FBI and the House and Senate intelligence committees are scrutinising the President's links to Russia.

Earlier, the White House denied it tried to stop potentially damaging evidence about links between Mr Trump's team and Russia from being made public.

Reports that government lawyers had tried to silence former acting attorney general Sally Yates have been described as "100% false" by White House spokesman Sean Spicer.

Ms Yates had been expected to tell a congressional intelligence committee on Wednesday what she knows about meetings between Mr Flynn and Russian ambassador Sergey Kislyak.

In letters made public by the Washington Post, a senior justice department lawyer was quoted as advising Ms Yates' lawyer that her inside information is "likely covered by the presidential communications privilege".

The lawyer added: "The President owns those privileges…she needs to consult with the White House."

When the White House was told she would not be silenced, a meeting of the House Intelligence Committee at which she was scheduled to give evidence was abruptly cancelled by its Republican chairman Devin Nunes, a former Trump transition team member.

Mr Nunes is leading one of three investigations into the swirling allegations of Russian interference in the election, while separate inquiries are being conducted by the Senate and the FBI.