One Nation Senate candidate Malcolm Roberts has defended his party's Far North Queensland candidate, Ross Macdonald, over pictures of him groping the breast of a "ladyboy" in Thailand, and others of Mr Macdonald posing with a topless woman.

Key points: Leichhardt One Nation candidate Ross MacDonald says he has done nothing untoward and won't resign

Leichhardt One Nation candidate Ross MacDonald says he has done nothing untoward and won't resign Mr MacDonald admitted he now regretted posting the photos on Facebook

Mr MacDonald admitted he now regretted posting the photos on Facebook Senate candidate Malcolm Roberts called the matter a "media beat-up"

The images emerged a day after the other One Nation Queensland Senate candidate Steve Dickson resigned over footage of him making derogatory comments and touching a dancer in a US strip club.

Speaking at a Cairns pre-polling booth on Thursday, Mr Macdonald, One Nation's candidate for the seat of Leichhardt, said he would not be standing down over the photographs he posted.

"No, I certainly won't, and I've done absolutely nothing wrong," Mr Macdonald said.

Mr Roberts suggested it was inappropriate to even question him on the matter.

"He was in Thailand for one of the photos and locally, here, for one of the photos," Mr Roberts said.

"At Gordonvale and in some pubs around here, they do topless barmaids and that's normal, so he hasn't broken the law here [and] he hasn't broken the law in Thailand.

"He was photographed, like many tourists, with a ladyboy in Thailand, I mean why would the ABC be wanting to pick on us again about this — this is ridiculous.

"Toplessness is local here, it's in the hotels in Gordonvale."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 44 seconds 44 s Steve Dickson caught on hidden camera at US strip club

Mr Macdonald said there was nothing illegal or untoward about the photos, but that he now regretted posting the material online.

"In hindsight, yes I do. I wish I'd never put any of that on Facebook," he said.

"But that was a long time ago for a start — in Thailand in 2015, and the topless girl in the pub selling raffle tickets, that was in Gordonvale in a pub about six years ago."

Mr Roberts confirmed with Mr Macdonald that the Thai "ladyboy" consented to the photograph.

"The ladyboy is actually a friend of mine on Facebook," Mr Macdonald said.

"This is a beat-up once again by the media to stitch up One Nation. We're tired of it," Mr Roberts said.

Earlier this week after Mr Dickson's resignation, tearful party leader Pauline Hanson told Channel Nine's A Current Affair the scandal had been used to attack her party unfairly.