A North Korean ship, the Kang Nam I, is anchored in Hong Kong waters on Tuesday, Oct. 24, 2006. AP-Yonhap

A Denmark-based company run by a British national fraudulently insured dozens of North Korean ships for years in violation of U.N. sanctions, keeping Pyongyang's foreign trade afloat, a Danish daily revealed Thursday.

DGS Marine, which is no longer in operation, issued insurance certificates to dozens of North Korean ships between 2011 and 2016, enabling them to sail in international waters, daily Information said, citing copies of the insurance contracts.

"According to our information, the number of certificates could be up to 100, which would represent just about the entire North Korean commercial fleet," one of the authors of the investigative report, Lasse Skou Andersen, told AFP.

DGS Marine, founded by British national David Skinner, had no authority to issue insurance certificates, the paper said. The company was shut down after Skinner's death in August 2016.

Hugh Griffiths, a former U.N. expert on North Korean sanctions, said the company played a key role in helping Pyongyang evade international sanctions by enabling the transport of sanctioned goods.

"The foreign currency generated by its coal, iron and oil exports is used to finance its nuclear and missile programmes," he told Information.

The newspaper's journalists uncovered the fraud when the company's name appeared as the insurer of two North Korean vessels in a 2017 report by a committee of U.N. Security Council experts.

Their five-year investigation identified at least 29 insurance certificates that had been issued by DGS Marine to North Korean ships despite the U.N. sanctions.

"These documents gave the boats access to foreign ports, enabling them to operate," Skou Andersen said.

In 2012, British daily The Telegraph revealed that David Skinner had insured Iranian tankers transporting Syrian oil despite U.N. sanctions.

"North Korea was not his only client. Everything seems to indicate that his business model was to insure boats in sanctioned countries," Skou Andersen said.

Skinner's son, Nicolas, who briefly took over the company before it folder, could not be reached for comment. (AFP)