British police have taken custody of 23 paintings previously ordered seized but not yet secured by authorities from a collector accused of financing Hezbollah.

In the raid, authorities with the National Crime Agency took full possession of paintings belonging to Nazem Ahmad from a Williams & Hill warehouse in Feltham, near Heathrow airport. Authorities also took possession of nine paintings that previously were intended to be auctioned by Phillips.

The seizure was revealed in a crime alert issued by the U.K.’s National Crime Agency (NCA) that highlighted it as case study of how alleged criminals conceal high-value assets in bonded storage facilities. Few details were given in the alert but the British publication The National and French publication Le Quotidien identified Ahmad as the person involved.

Artworks seized in the raid include a linocut by Pablo Picasso titled Nature morte a la pasteque (1962) and Andy Warhol’s Details of Renaissance Paintings (Leonardo da Vinci, The Annunciation, 1472). The most valuable works seized include the Stanley Whitney painting Sing All Day, worth £225,000 ($315,000), and Iranian artist Ali Banisadr’s painting Divine Wind, valued at £175,000 ($221,000). Altogether, the works seized are worth about £1 million, or nearly $1.3 million.

Ahmad, a 59-year-old Lebanese businessman and collector believed to be living in Beirut, was previously sanctioned by the United States in December 2019 and accused of laundering money for Hezbollah and its leader Hassan Nasrallah. The British government also froze his assets at the time.

Last March, Ahmad was indicted in a Brooklyn federal court for violating terrorism-related sanctions. Hezbollah is a major Shiite political party in Lebanon, with an armed militant wing. The U.S., and its allies including Israel and the U.K., consider it to be a terrorist group.

Authorities in both the U.S. and U.K. have forbidden artists, galleries, and auction houses from doing business with him and his Artual gallery in Beirut, run by his daughter.

Phillips has been working with the U.S. authorities on this case since 2019 when Mr. Ahmad was first known to be suspected of wrongdoing, according to the auction house. “As a regulated business, we have strict internal procedures which ensured that Mr. Ahmad was banned from transacting with us and we froze all artworks belonging to Mr. Ahmad in our possession globally at that time,” a Phillips spokesperson said in an email.

“We also provided a full list to the U.S. Department of Justice of all properties held by us belonging to Mr. Ahmad, which included some items stored in the U.K. When, some years later the U.K. police requested to take possession of the property belonging to Mr. Ahmad, Phillips fully and promptly complied.”

Hezbollah and the NCA did not respond to a request for comment by press time.

The NCA alert was aimed at U.K. artwork storage facilities, specialist service providers that are linked to the art storage sector such as galleries and auction houses, and the clients that utilize these art storage facilities.

“As the price of art has increased, contemporary collecting has grown, with owners more interested in seeing their artwork investment portfolios appreciate in value,” the document said. “It is prompting concerns about the use of these storage facilities for illegal activities by criminals seeking a capital asset that can be safely stored, that appreciates in value over time, and that can be liquidated if and when required.”

The NCA also said it estimates that “millions of pieces of art are currently held in specialist storage and have not left those facilities in decades.”