THE captain of a Chinese research vessel which sank in a collision with a tanker north of Taiwan has accused the tanker's master of refusing to send lifeboats to pick up survivors, escalating the dispute over responsibility in the incident. But the Greek master of the Silver Horn challenged the allegation, made in a statement typed in English on board his ship as it lay about 20 nautical miles off the coast of South Korea. The statement, a copy of which was obtained by the South China Morning Post, purports to be a joint ''Confirmation Notice of Collision'', with positions at the bottom designated for the two captains to sign. It says the Chinese research vessel Xiang Yang Hong 16 had identified a number of ships ahead of it with the help of its radar, because of the poor visibility, and had manoeuvred correctly under international regulations to avoid collision with the Silver Horn. The tanker took no action, it says, and the Xiang Yang Hong 16 was struck at 5.05 am on Sunday and sank 35 minutes later. ''After collision, two lifeboats of Xiang Yang Hong 16 were heavily damaged. During our self-rescuing, we requested Silver Horn again and again to send its lifeboats to help us, but no lifeboats were sent to us. ''This is not humanist,'' the statement says. Although the statement does not explain how, it says that all but three of the 110 crew boarded the Silver Horn. The three are now missing presumed dead. ''Silver Horn shall be responsible for all the great loss occurred therefore,'' the statement says. The Chinese captain's signature appears on the right. On the left, the Silver Horn's captain has handwritten a notation which reads: ''I disagree with the line saying that we did not send our lifeboats. We started preparing lowering. But found unnecessary due to the fact that all people were into their lifeboats.'' Just above his signature he printed ''Only for receipt'', indicating that he may have been signing only an acknowledgement of what the statement said, but not necessarily that he was accepting responsibility as stated. Hongkong lawyers for the Silver Horn said their captain had been given an ultimatum by China, which sent a naval gunboat and a tug to meet the vessel, to sign a statement of liability or sail to Shanghai. About 30 of the Chinese seamen and scientists he had earlier rescued had confined him to the bridge with his chief officer. Lawyer Mr George Eddings said the captain had ''no option but to sign'' fearing further damage to his leaking tanker if he sailed to China, and possible criminal charges against him and his crew in Shanghai. ''We simply don't have a great deal of trust in their court system, which was another factor. ''The whole statement was given under clear duress and despite the fact that China had no jurisdiction,'' Mr Eddings said. China had no right to take such jurisdiction in international waters, he said. Once the Chinese authorities were satisfied, the survivors were placed aboard a salvage tug at about 11 am yesterday. The Silver Horn is now expected to limp into the southern Korean port of Ulsan today, its cargo of chemicals intact. Lawyers will travel to South Korea to prepare a new statement of fact for possible civil action on both sides. Meanwhile, Cyprus, flag-state for the tanker, has issued a strong diplomatic protest to China, demanding explanations for what it sees as a hijacking in international waters. Questions have also been lodged with the New China News Agency in Hongkong and the Chinese embassy in Cyprus. ''This is unacceptable heavy-handedness in international waters and we have told them so,'' a Beijing-based Cypriot diplomat said yesterday. No word has yet been heard from China.