Exactly what the measures mean for existing Mansudae art has yet to become clear. In Beijing's art district, a gallery called the Mansudae Art Gallery says it is the studio's official overseas gallery. Its head insists the sanctions do not apply to it and says they have had no impact on his business.

"Now more than ever we need avenues like art to create understanding between North Korea and the rest of the world," said Ji Zhengtai.

It is not possible to estimate the total value of Mansudae's dealings, but the Security Council diplomat said the business had earned tens of millions of dollars globally.

"We Don’t Do Politics"

Mansudaeartsudio.com, a website in Italy which calls itself Mansudae's "official website abroad," says the studio is "probably the largest art production center in the world."

Mansudae's Pyongyang studio covers 120,000 sq m (nearly 30 acres), employs about 4,000 people including around 1,000 artists, and is divided into 13 creative groups, seven manufacturing plants and more than 50 supply departments, the website says.

The website is run by Pier Luigi Cecioni, who sells Mansudae works online and at fairs through what he calls an exclusive agreement with Mansudae Art Studio. He declined to say how much he sells, but in August after the sanctions on Mansudae Art Studio were announced, he told Reuters that the revenues go direct to the studio to pay for paints and equipment.

Cecioni said he sells works from his personal collection, most of them bought several years ago - before sanctions on Mansudae were announced. His website makes clear that any online purchase is made with his Italian company, not Mansudae. U.N. sanctions are not retroactive.

A panel of independent experts is charged with monitoring U.N. sanctions on North Korea. It reports violations and recommendations to the Security Council's North Korea sanctions committee. Its reports are confidential, but the committee traditionally publishes annual reports.

Hugh Griffiths, who heads the panel, declined to comment, saying "the matter is subject to an ongoing investigation."