Paul Burrell has reportedly signed a six-figure deal to be interviewed by the Daily Mirror.
His story will be serialised in the tabloid from tomorrow, according to the newspaper's editor Piers Morgan.
It is thought Princess Diana's former butler will reveal for the first time the evidence he would have given in the witness box.
Piers Morgan told Sky News the paper had paid Burrell "less than £500,000 but more than £250,000" for the inside story of his trial.
Mr Burrell was formally found not guilty of three charges of stealing from the estate of Princess Diana and Prince William. The case against him was dropped, following an intervention by the Queen.
Mr Burrell is also thought to be in talks to appear on ITV's Tonight With Trevor McDonald.
PA
