Houston ? Former Enron Corp. Chief Executive Jeffrey Skilling ended lengthy testimony in his federal fraud trial Thursday by denying a new government accusation – that he may have cheated on his taxes.

Skilling calmly said he didn’t recall backdating a $10,000 gift check to an ex-girlfriend to avoid paying taxes on it in 1998, and he told jurors that he has heard nothing from the Internal Revenue Service despite repeated reviews of his tax returns.

“I paid my taxes,” he testified – more than $66 million from 1997 through 2004.

Skilling’s co-defendant, Enron founder Kenneth Lay, will take the witness stand Monday after another witness testifies briefly on Skilling’s behalf.

The former CEO repeatedly denied during 7 1/2 days of testimony that he lied to investors about Enron’s financial strength or approved accounting tricks to meet earnings targets and impress Wall Street.