A trove of stolen paintings by Abstract Expressionist master Hans Hofmann has been recovered by agency Art Recovery International, more than a decade after they were stolen from a fine art storage space in Manhattan.

The five paintings, worth just over $500,000, were last seen at Cirkers Hayes warehouse in 2003. The works were owned by a trust known as the Renate, Hans and Maria Hofmann Trust.

Courtesy of Art Recovery International, London.

According to a release from Art Recovery, the thefts were an inside job by a longtime Cirkers caretaker, John Rett, who “used the storage facility as his personal shopping center, removing hundreds of thousands of dollars worth” of paintings and sculptures and selling them through venues—including auction houses, galleries, and art dealers—all over the world.

Courtesy of Art Recovery International, London.

Rett was reportedly the trust’s main point of contact during the time that the works went missing.

This isn’t the first time the caretaker was linked to stolen art. According to information from Art Recovery International, Rett was arrested by the New York City Police Department in 2004 after he was caught trying to sell several sculptures at Christie’s in London as well as at an unnamed New York City gallery. The sculptures were taken from Cirkers storage facility.

Art Recovery says the sculptures were recovered and returned to Cirkers but that police closed the criminal case without executing a search warrant on Rett’s residence. Rett received what seems to be an incredibly light sentence of 10 days in jail. He also had a petty larceny request on his record from 1975, according to a Daily News report on the theft of the sculptures.

As for the Hofman paintings, one of the artist’s works led to the recovery of the others. In 2016, Hofmann’s The Artist was consigned for sale at Heritage Auctions New York, but it went unsold. The same work was then consigned to Swann Galleries this year, where it was retrieved by Art Recovery.

Courtesy of Art Recovery International, London.

After further investigation, the Swann consignor, who is reportedly a New York City dealer, was persuaded to come forward with four more stolen Hofmann works, which he eventually released to Art Recovery. The agency says a sixth Hofmann work, titled Arcanum, is still missing.

“I’ve seen this all before,” said Art Recovery International CEO Christopher Marinello in a statement. “A classic case of all too often repeated insider theft on a grand scale. Thieves take advantage of the so-called legitimate distribution network for stolen artwork and the lack of interest in serious due diligence by the art trade.” Marinello says he still sees a reluctance by the trade to “pay the cost of proper due diligence out of fear that it will get in the way of earning a profit.”

At publication time, there was no word of Rett’s current whereabouts or whether he has been charged with or arrested for the theft.

The current auction record for Hofmann is $8.9 million, set at Christie’s New York last month for Lava (1960), which carried an estimate of $4 million to $6 million. To date, more than 25 Hofmann works have sold for more than $1 million each, according to the artnet Price Database. More than 900 works by Hofmann have come to auction.