Wikipedia – On 18 may 1951 COSSACK intercepted the cargo ship Nacy Moller off Hainan.China. The ship was carring a cargo of rubber bound for a Chineses port in contravention of a United Nations embargo. Nancy Moller was escorted back to Hong Kong. On 12 May 1951 Nancy Moller departed from Singapore bound for Whampoa, China. She was carring a cargo of 3,500 long tons (3,556 tons) of rubber destined for China in contravention of an export ban. On 18 May she was intercepted by HMS Cossack off Hainan island, China and escorted back to Singapore. The interception was carried our under Regulation 53 of the Emergency Powers Act ( Defence) Act 1939, which gave the British Government powers to requistion any ship on the British or Colonial register and order the ship to proceed as directed.. An agreement had been made between the British government and the governments of the Federation of Malaya and Singapore to limit exports of rubber to China to 2,500 long tons ( 2,540 tons) per month from 9 April 1951. The embargo was part of a United Nations embargo against China, which was supplying arms to Kim II-s Sung’s forces in the Korean War. Nancy Moller reached Singapore on 23 May. Her cargo was stated to be worth S$2,000,000 ( then £1,000,000). Her cargo had been covered by an export licence that had been issued before the embargo came into force.