LNP leader David Crisafulli says a candidate's decision to joke about her German heritage after her poster was defaced with a Hitler moustache was unfunny and "wrong".

Cairns LNP candidate Bree James posted a photo of herself beside the vandalised banner yesterday afternoon, with a caption spruiking a local German festival.

"Even my banner is getting in the spirit and celebrating my German heritage," she wrote.

Ms James has apologised and taken down the post.

Speaking at the party's official campaign launch in Ipswich today, Mr Crisafulli said he had spoken to Ms James, who had "expressed genuine remorse".

"Is this acceptable? It's not. It's disappointing, it's wrong, it's not funny. And I've expressed my view to her very clearly," Mr Crisafulli said.

"She knows my view and and I've made it very, very clear to her."

Ms James has been contacted for comment.

Anti-Defamation Commission chair Dvir Abramovich said it was "beyond a misguided joke" and "trivialised the atrocities of the Holocaust". 

"This kind of thoughtless post is not just offensive — it sends a message that Nazi symbolism can be casually used, as though it were part of a lighthearted joke," he said.

Asked about Ms James's post, Labor leader Steven Miles said he was "not going to pile on too hard there". 

Earlier this month a photo emerged from the 1987 high school yearbook of Labor MP for Caloundra Jason Hunt that showed him wearing a T-shirt depicting Adolf Hitler giving a Nazi salute. 

He said it was a "satirical T-shirt" that was "widely available" at the time.

Today, Mr Crisafulli expanded on his plan for remote detention centres to reform young offenders, if elected on October 26. 

He said the LNP would make education compulsory for all young detainees — although the government countered that such a requirement was already in place.

"It's a mixture of compassion and discipline," Mr Crisafulli said of the party's plan, Detention with Purpose. 

He also promised to introduce a minimum time in isolation for detainees who assault detention centre staff — a measure which he said would improve staff retention.