Mud and mould on Lindauer portraits returned after heist

If only they could talk - two valuable Lindauer paintings stolen then mysteriously returned have traces of mud, mould and a puncture, but can be repaired, an expert says.

Chieftainess Ngatai-Raure and Chief Ngatai-Raure were painted in 1884 by Gottfried Lindauer and the portraits had a combined value of about $1 million when they were stolen in a 2017 ram raid at Parnell gallery the International Art Centre.

Police said they were recently contacted by an intermediary, who wanted to return the paintings on behalf of others. And the damaged works are now back with their rightful owners.

Their reappearance was a shock, but "good news all round", Auckland International Art Centre director Richard Thomson told Checkpoint.

The gallery was "in the dark as much as you are" about the journey they had been on after they were taken, he said.

"I always thought they were here ... all this talk at them going off and being in a palace in Shanghai or wherever, was all just fantasy in my opinion, I had a funny feeling they may have still been in Auckland, and I still think they were probably in the Auckland region when they were found ... who knows?"

The paintings appeared to have not been removed from their frames, he said. But during the ram-raid one of the pictures was so badly banged that a piece of frame was left embedded in the side of the gallery.

"They are damaged on the surface for sure, and one of them has a puncture hole, but things can be repaired ... it's a painstaking process.

"I would say they were in a place where they haven't been looked after, temperature controlled or anything like that, there were slight mud stains on one of the frames and there's some mould on the surface of one of the paintings.

"I feel quite responsible to make sure that these paintings are properly restored, and if they do come back onto the market we'll be very clear and people will see how they are."

Thomson said the theft was now part of the paintings' providence and story.

"It's a total mystery - it was a brutal assault on our business, and a brutal assault on the New Zealand art market, and it affected a lot of people at the time."