A high-profile art collector has been put on a Treasury sanctions list and charged in the US over claims that he uses his collection, which has included masterpieces by Pablo Picasso, Antony Gormley and Andy Warhol, to launder money for the Lebanese militant group Hezbollah. Nazem Ahmad, a diamond and art dealer who once posed in his Beirut penthouse for a glossy magazine and featured in a piece about the “world’s most beautiful homes and the fascinating people who live in them”, has been targeted in the UK under new counter-terrorism powers. He had previously been put on a sanctions list by the US Treasury, and on Tuesday, a New York court charged him, along with eight co-defendants including his son and daughter, of defying those prohibitions by completing art and jewel transactions worth $160m since 2019. An unnamed suspect was arrested in the UK as part of the US investigation. Ahmad, who has not yet been located, did not respond to a request for comment when approached by this newspaper via his gallery in Beirut or on social media. In the UK Treasury’s announcement of sanctions, Ahmad had been described as a suspected financier of Hezbollah, a Shia Muslim political movement backed by Iran and which the UK government classified in its entirety as a terrorist group in 2019. According to the Treasury, Ahmad, who has 172,000 Instagram followers, has a large art collection in the UK and is well known in the British art community, where he is said to have worked with “multiple UK-based artists, art galleries and auction houses”. All of Ahmad’s assets in the UK, including what has been described as an “extensive art collection”, have now been frozen, the Treasury said, and British artists, galleries and auction houses have been prohibited from trading with him or six named companies, including his Artual gallery in Beirut, which is run by his daughter, Hind Nazem Ahmad. The Treasury minister in the House of Lords, Joanna Penn, said: “We will always proactively defend our economy against those who seek to abuse it. The firm action we have taken today will clamp down on those who are funding international terrorism, strengthening the UK’s economic and national security.” Ahmad is accused of using art to shelter and launder money for the purposes of terrorism. The use of art, a sector that historically tends towards discretion and the protection of privacy, for the purpose of laundering involves the buying and selling of high-valued pieces to disguise the origins of illegally obtained funds. Pieces can be relatively easily sold across national borders without alerting the authorities. The subjective nature of the value of art allows prices to be easily inflated or deflated. The antiquities, art and cultural object market is said to have had a global value of $65.1bn in 2021, according to the Financial Action Task Force, an intergovernmental laundering watchdog that issued a report in February to advise on regulatory best practice. Five years ago, Ahmad featured in articles in the Architectural Digest Middle East and the Selections Art magazine. It was claimed his collection included works by Jean-Michel Basquiat, Ai Weiwei, Thomas Heatherwick and Marc Quinn, among others. During an interview, Ahmad also spoke of his first art purchase, which he described as a work on paper by Picasso, bought in the early 1990s. In 2019, the US Treasury had imposed sanctions against Ahmad and two others, describing him as the personal financier to the Hezbollah secretary general, Hassan Nasrallah. Ahmad had been considered a “major Hezbollah financial donor” since 2016, they said. According to a nine-count indictment unsealed on Tuesday in the US district court for the eastern district of New York, Ahmad and his co-defendants had defied those sanction and had since 2019 “relied on a complex web of business entities to obtain valuable artwork from US artists and art galleries and to secure US-based diamond-grading services, all while hiding Ahmad’s involvement”. In a statement, the US Department of Justice (DOJ) said Ahmad had commissioned works and negotiated their sale all while insisting that his connection was kept from public view. “Approximately $160m worth of artwork and diamond-grading services were transacted through the US financial system,” the DoJ said. “One defendant was arrested today in the United Kingdom at the request of the United States, and the eight remaining defendants, including Ahmad, are believed to reside outside the United States and remain at large.” Ahmad has previously denied reports that he was linked to financing Hezbollah.