OAKLAND, Calif. -- Software programmer Hans Reiser testified Monday he had nothing to do with his estranged wife's disappearance.

Reiser, 44, said he has tried to figure out what may have happened to Nina Reiser, who hasn't been seen since dropping the couple's two children off at Reiser's house on Sept. 3, 2006.

Before leaving the house, Reiser said he talked to his wife for about an hour, discussing their children and their divorce, and said he "put a lot of pressure" on Nina Reiser, including accusing her of embezzlement and perjury.

Nina Reiser's body has not been found and the defense has suggested she could still be alive and living in her native Russia.

But prosecutors say she was not the sort of person who would abandon her children. They say DNA and other evidence points to Hans Reiser. Among other things, Reiser's car was found with the passenger seat missing and the floorboard soaked with water.

Reiser began his fourth day of testimony Monday following a weeklong hiatus in the trial.

Although the two had been in a contentious divorce, Reiser said Monday their relationship had been improving and they had started to do activities with the children, such as going to soccer practice.

Reiser went over the events of Sept. 3, reiterating his earlier testimony that Nina Reiser had offered to give him control of his company, Namesys, but refused his request for legal custody, which the courts had awarded to her.

Nina Reiser then said she had to go and called the children, who were playing in another room, to say goodbye, Reiser said.

He said he watched her walk out of the house and she looked "magnificent."

Reiser recalled that moment as "a mix of emotions." He sighed and paused frequently as he sought to explain those emotions, finally saying he was "unhappy," and "it's only the lawyers who win in divorces."

But he added that he wasn't thinking about lawyers at the time.

"I was thinking that I wanted to go downstairs and play with the kids," he said. "That was really the main thing I was thinking about."