Saskatchewan Justice Minister Don Morgan should resign after telling a variety of different stories about the person who leaked police reports, the NDP Opposition says.

Last year, the Saskatchewan Party used the leaked documents to attack the governing New Democrats in the legislature.

The files concerned a Regina police investigation in the early 1990s into about $6,000 taken from the NDP caucus by a former employee. No charges resulted, and the then-opposition Saskatchewan Party wanted to know why. A second police investigation resulted in no recommendation that charges be laid.

A police investigation into who leaked the confidential files didn't result in charges either, although police said they suspected a certain Regina police officer was the leaker.

In recent days in the legislature, Morgan has provided different versions of his contacts with the man, who hasn't been named.

At first, Morgan said he'd never spoken to the officer: "I have not."

Later he admitted he had, on the phone: "Yes, I have on an unrelated matter some years ago."

After saying he spoke to the person on the phone, Morgan said he'd never met him: "He's not known to me. If he was standing in this scrum I wouldn't know the individual. I would not."

That version was put to a further test Thursday, when NDP justice critic Frank Quennell released a letter written to the man in question from Morgan several years ago, in which Morgan admitted he did meet with the officer.

Morgan dealt with that latest development by talking to reporters. He said it was an innocent mistake.

"I stand corrected by my own letter," he said. "My recollection is that I had a conversation with him and that I wrote a letter and clearly, that's not correct."

Morgan said his memory isn't perfect, but he wasn't trying to be deceptive.

However, Quennell said he doesn't believe what Morgan says now.

"Everything he says about this turns out to be not true," Quennell said. "I don't give him the benefit of the doubt any more."

Morgan should step down while the matter is investigated, he said.