Anselm Kiefer’s works aren’t just valued among collectors—they’re popular with thieves too. 

A sculpture by the German artist made of lead was damaged late last night when robbers broke into his studio in Paris. According to the AFP, the thieves broke into Kiefer’s warehouse after midnight by cutting through the fence surrounding the property. 

At around 1:30 a.m., they were interrupted by a security guard while trying to dismantle a large, book-like sculpture. The criminals fled.

“These thieves did not realize the value of the work,” a source told the news agency. “They were mainly after the lead, which is valuable, especially in this form.”

Assistants set up the artwork Frauen in der Antike by Anselm Kiefer at the Kunsthalle in Mannheim. Photo: Uwe Anspach/dpa via Getty Images.

The sculpture is likely one that is made from lead that Kiefer purchased in 1985 when it was stripped from the Cologne Cathedral, which was undergoing renovations that year. (He has used lead from the church in many of his works.) The artist has long been interested in the material’s usage throughout history.

Kiefer’s properties in France, where he has lived since the early 1990s, have been targeted a number of times by thieves, most recently in 2016 when a team of burglars pilfered a book sculpture made of 10 tons of lead and 12 tons of marble.

The work, which was locked in the courtyard of the artist’s warehouse, was valued at roughly $1.65 million.

In late 2007 and early 2008, 22 lead sculptures, which altogether weighed 7.5 tons, were stolen from Kiefer’s previous studio in Barjac, France. The lead turned up several days later when it was sold as scrap.