Stormy Daniels, the porn star who was paid to keep quiet about her affair with Donald Trump, sued the president, alleging that her nondisclosure agreement before the 2016 election is void because Trump failed to sign it.

In the lawsuit filed today in Los Angeles Superior Court, Daniels - whose real name is Stephanie Clifford - said she wanted to go public with the story of her affair with Trump in the weeks leading up to the 2016 presidential election.

Trump's lawyer, Michael Cohen, and Daniels's attorney, Keith Davidson, negotiated what the lawsuit calls a "hush agreement" in which she would be paid US$130,000. After delays and even a wholesale cancellation of the contract by Daniels on Oct, 17, the payment arrived on October 27, 12 days before the election, according to e-mails reviewed by The Washington Post.

Cohen said recently that he used his own money to "facilitate" the payment.

The lawsuit suggests Trump was aware of the agreement and that the money was intended to influence the outcome of the 2016 election, bolstering two complaints filed with the Federal Election Commission that say the payment violated election law because it was not reported as an in-kind campaign donation.