Whether or not two "deceased" toes stolen from an exhibition in Auckland are truly human was at the centre of a court hearing today.

Upper Hutt man Joshua Putaone Williams wandered into the Body Worlds Vital exhibition in May and "plucked" two human toes from one of the displays, which he pocketed and took away.

The anatomical displays are made up from bodies and organs donated for science.

The 28-year-old reappeared in court today for sentencing on charges of theft and interfering with human remains, but ended up escaping conviction.

Judge Bill Hastings said in the Wellington District Court this afternoon he considered Williams' actions "impulsive".

"You couldn't resist the temptation to touch what presented to you as a dead body."

Williams had wandered up to an uncovered display, leaned over, and touched the toes of a female acrobat.

"You say the toes flicked back and you took the index toe and the middle toe. You put the toes in your pocket and left the exhibition."

"You later posted a picture to Instagram of you holding the toe, with the caption, and I quote 'Chur to the Body World festival, I stole a toe from an uncovered display lol'," he said.

Williams returned the toes to police and pleaded guilty earlier this year to theft and interfering with human remains, but Judge Hastings today raised concerns that he had been "totally overcharged".

He said Williams could not be charged both with theft and with interfering with remains.

Case law showed that human remains could not be considered "property" and so could not be the subject of a theft.

However, Judge Hastings questioned whether the toes were even human following the process the corpses went through to be put into the exhibition.

The exhibition "consists of what were once human corpses", he said.

"Their skin has been removed and what is left has gone through a process of plastination ... effectively turning them into plastic. They are then put in various poses and subjected to gas, heat, or ultra-violet light to harden them in these poses."

Judge Hastings said it could be argued the plastination process removed so much of the original material that the bodies were no longer human, but merely plastic objects.

But if they were to be considered human, the theft charge had to be dropped.

After discussion with the police prosecutor in court, it was decided the toes were still human, and that the theft charge should be thrown out.

He did not want Williams to have the interfering charge on his record, saying it "conjures up an image of a cloth-hatted grave robber with a shovel, digging up graves in a cemetery at night".

"What you actually did was pluck two toes from a plastified body."

He said the stigma of the conviction would be out of proportion to the gravity of the offending.

Judge Hastings discharged Williams without conviction on the interfering with human remains charge.

He said it could be argued the improper interference began well before Williams took the toes - when the bodies were initially put through the plastination process and again when they were moved around and posed for a paying audience.

The toes cost about $5500 to reaffix.

Williams had four previous convictions, none of which were for similar offending. He has not offended for seven years.

Williams pleaded guilty in the Wellington District Court earlier this year to the bizarre offending, in which he wandered up to a display of human corpses and "plucked" a middle and index toe from a body, according to the summary of facts.

He gave the middle toe to an unknown male, and kept the index toe as a "souvenir", posting on social media about the theft.

"... I stole a toe from an uncovered display lol," he wrote in the post on Instagram, along with a photo of the toe.

Police have since recovered the toe from him.

The toes cost approximately $5485 to re-affix.

When asked by police about the crime, Williams said he didn't plan the offending.

"I saw them so I took them, sorry," he said.

Body Worlds Vital is a travelling exhibition of human remains that have been preserved through plastination, their fluids and fats swapped with plastics.

The show arrived in New Zealand in April, the first time it had been in the country.

Dr Angelina Whalley and her husband Dr Gunther von Hagens, who invented plastination in the 1970s at the University of Heidelberg to teach students about anatomy, established Body Worlds in 1997.

Since then more than 17,000 people have donated their bodies to von Hagens' Institute for Plastination, which also sends plastinated specimens to medical schools around the world.

More than 45 million people worldwide have seen the exhibition.