The closest call was on May 9, when the Royal Thai Navy, acting on intelligence supplied by Australia, detected the Sun Sea in the Gulf of Thailand. But the ship was let go because it was outside Thai territorial waters.

Another chance came later in May, when the ship was reported to be having engine trouble in Cambodian waters. Canada asked for Cambodia’s help but Phnom Penh would not intercept the vessel, an official said.

The UN Refugee Agency also said it had received a fax purportedly from a Sun Sea passenger in July. The letter said the ship was destined for Canada with hundreds of Sri Lankans but was having engine trouble. The agency was unable to verify the letter’s authenticity.

When the Sun Sea appeared out of the summer sea fog off the British Columbia coast last week, few in the Canadian government were caught by surprise. The ship may have been one of the worst-kept secrets in the history of organized smuggling.

But repeated chances to prevent the crammed cargo vessel from making the risky Pacific crossing were lost, illustrating the apparent inability of governments to stop profiteers from exploiting the desperation of migrants.

“There’s no doubt that we, Australia and a lot of people knew about this ship and were it not for legal constraints, could have seized this ship,” a Canadian official said. “Everyone felt powerless by the current legal regime to do anything about it.”

If the smuggling kingpins are closely watching Canada’s response to the Sun Sea, as Public Safety Minister Vic Toews has said, they may well be encouraged. Even in a case where Ottawa was tipped off in advance, it was unable to do more than prepare for the ship’s arrival.

The story of the Sun Sea, pieced together from interviews and documents, appears to underscore the need for greater international co-operation and changes to existing laws if the maritime migrant smuggling industry is to be curbed.

In late March and early April, Canadian officials were hearing that vessels were gathering in Thailand and that they could be destined for Canada. By mid-April, Canada got word that two vessels were in and around the Gulf of Thailand and that they were potentially coming to Canada.

Australia alerted Thailand to the Sun Sea.

“The Royal Thai Navy monitored the activities of the vessel, but we did not board the ship,” said Cherdchai Chaivaivid, Counsellor and Head of Chancery at the Royal Thai Embassy in Ottawa.

He said the navy detected the ship within Thailand’s 200-mile exclusive economic zone. But it was outside Thailand’s 12-mile territorial limit and therefore could not be boarded.

“I presume that we had no authority to search the vessel, as we would have had to have received a request by the flag state. At the time the ship was flying no flag at all.”

Mr. Chaivaivid said the navy communicated with the shipmaster to determine the ship’s nationality, and was informed that the MV Sun Sea was not registered to Thailand. The ship reportedly made no attempt to enter Thailand’s territorial waters.

“We monitored the vessel, and it eventually left our economic zone heading east on May 9,” he said, adding that the ship was then believed to be carrying “just above a hundred people on board.”

Mr. Chaivaivid said he had no evidence the operation was staged out of Thailand. But Mr. Toews said it was, and Canadian Tamil Congress legal advisor Gary Anandasangaree agreed that appears to be the case. “Most people have said Thailand was their starting place,” he said.

Later in May, the Canadian government learned the ship was in Cambodian waters. It was said to be having engine troubles and travelling at only a slow speed, no more than a few knots. The Cambodian government was not interested in intercepting the vessel, an official said.

The UNHCR office in Bangkok, meanwhile, was receiving what it called “sketchy” reports about the ship. In July, a fax arrived purporting to be a letter from a passenger on the ship.

The author of the letter, dated June 20, wrote that after travelling from Sri Lanka to Bangkok, a broker brought him to the Sun Sea.

He said when he boarded there were already 300 Sri Lankans aboard. The ship had been off Thailand for two months and was having engine trouble, the letter said. He said the ship would be sailing to Canada.

“Although unverified, this information was immediately passed to the Thai authorities,” Andrej Mahecic, a UNHCR spokesman, said from Geneva yesterday. “A few days later we were told by the Philippine authorities that the MV Sun Sea might be approaching Philippine waters. We did not, however, receive any further information.”

The UNHCR communiqué to Bangkok, indicating the ship was probably in the Philippines, was dated July 12. According to Mr. Toews, the Sun Sea sailed between the Philippines and Japan before crossing the Pacific.

The Sun Sea arrived in Canadian waters off Vancouver Island at 2:41 p.m. on Aug. 12. It was intercepted by the Navy, boarded by the RCMP and brought to CFB-Esquimalt near Victoria. The Canada Border Services Agency is now screening the passengers and crew.
Mr. Toews has said the passengers paid $40,000 to $50,000 each for the voyage, which he alleged was a money-making operation organized by elements of the Tamil Tigers. The RCMP is investigating the smuggling network, which may link back to Canada.