Scandal, hush-money payments, secret recordings and Donald Trump's alleged gag order violations took centre stage during his tenth day in court.

The court heard testimony from Keith Davidson, a lawyer who brokered porn star Stormy Daniels' hush-money deal.

Questioning of Mr Davidson grew hostile, as the defence tried to paint him as a sleazy Hollywood profiteer.

He pushed back, alleging the defence had wrongly used words like "extortion" to describe valid legal settlements.

"We're both lawyers. I'm not here to play lawyer games with you," the ex-president's lawyer Emil Bove said on Thursday in a particularly heated moment during cross-examination.

Mr Bove unearthed several celebrity scandals that Mr Davidson allegedly was involved in keeping quiet, apparently in an effort to shake the witness' credibility.

Mr Trump's lawyer asked whether Mr Davidson had "extracted sums of money" from actor Charlie Sheen and if he worked with a "sex-tape broker" on the behalf of reality star Tila Tequila. There were also stories about actress Lindsay Lohan's visit to a rehabilitation facility and professional wrestler Hulk Hogan's sex tape.