Former Labour Party minister Dover Samuels has stuck up for Richard Worth, saying he had advised him to "hold his head high and walk back into that Parliament".

Mr Samuels was the first minister disciplined under Helen Clark's Labour Government.

After refusing to resign, he was stood down as a minister in 2000 during a police investigation into allegations of historic sexual misconduct. No charges were laid, but Mr Samuels was not reinstated to the Cabinet, although he became a minister outside the inner sanctum in 2002.

Yesterday, he said he had spoken to Dr Worth recently and told him that if he had done nothing wrong and his family stood by him, he should return to Parliament.

He also criticised Labour leader Phil Goff, saying he had stooped to "sewerage politics" in the way he had handled allegations made by Neelam Choudary that Dr Worth had sent her inappropriate texts and phone calls.

He said Mr Goff had started off like a "statesman" by going directly and quietly to the Prime Minister.

"That's where he should have left it. I don't think it behoves anybody to perpetuate gutter politics."

Dr Worth had not been given the chance for his side of the story to come out, partly because of police investigations into sexual allegations by a Korean woman, he said.

"Only the people involved know the truth and I think Richard Worth should have had his day so that his story could be told. It will be an interesting day when and if he gets time to tell his side of the story, and interesting if the police decide there are no grounds for prosecution."

However, even if a besmirched politician was later cleared, there was little chance of redemption.

"It's very difficult for those who made accusations and pulled the guillotine to be able to apologise. Once the dirt has been thrown, it tends to stick," said Mr Samuels.

Former MP Katherine Rich said Dr Worth's resignation was "sad news" but reflected his "deep loyalty to the party he loves".