But the result was immediately placed under protest by the race committee, which alleged Investec Loyal had used a television helicopter pilot to spy on Wild Oats XI.

The protest under rule 41, which refers to the use of outside assistance, will be heard at the Royal Yacht Club of Tasmania at 10 a.m. Thursday AEDT (2300 Wednesday GMT).

The race committee, chaired by Tim Cox, alleges the incident occurred at 6.30 a.m. on Tuesday (7.30 p.m. Monday GMT), 30 nautical miles south of Merimbula on the south coast of New South Wales State.

The protest describes an "audio recording of (a) conversation between ABC helicopter and Investec Loyal. Crewman from Investec Loyal seeking information from the helicopter of the sail plan in use on Wild Oats XI." In a dramatic final day, Investec Loyal overtook Wild Oats XI mid-afternoon and held on in a tight, tactical tussle to reverse last year's finishing order, crossing the line just ahead of its rival after 628 nautical miles of racing.

The 100-foot Investec Loyal, skippered by Anthony Bell, finished at 7.17 p.m. local time (0815 GMT), 2 days, 6 hours, 14 minutes, 18 seconds after leaving Sydney.

The race was the first since 1997 to still be actively contested in the Derwent River which leads to the finish line off Constitution Dock in Hobart, capital of the island state of Tasmania.

Wild Oats XI led for most of the race but finished 3 minutes, 8 seconds behind Investec Loyal. The finish was the closest in a generation, but was well outside the narrowest margin in the race's history: The 7 second gap between Condor of Bermuda and Apollo in 1982.

Third-placed Lahana was about 50 miles from the finish line when Wild Oats XI crossed and was expected to finish after midnight local time. Fifth-placed Loki, which had 60 miles to run, was narrowly leading the race on handicap when Investec Loyal finished.

Loyal's narrow win capped an exhilarating final 24 hours in which the lead changed hands three times. Wild Oats had led the 88 yacht fleet out of Sydney Harbor on Monday at the start of the 67th edition of the race and held that lead through a stormy first night at sea, then through all of the next day.

Investec Loyal closed, then overtook Wild Oats on Tuesday night and led by a little more than one mile when dawn broke over a reduced fleet on Wednesday.

Wild Oats XI, skippered by Mark Richards, regained the lead on Wednesday morning and had opened a four mile lead by mid-afternoon which seemed to ensure its sixth line honors success.

But Investec Loyal again closed then overtook Wild Oats XI in lighter winds, leading by seven minutes when it rounded Tasman Island, heading for the mouth of the Derwent.

The yachts remained in sight of each other in the final hours of the race, and were seldom separated by more than a third of a mile. Wild Oats XI set the race record in 2005 and showed greater speed at times but Investec Loyal was able to cover its every move in the last 20 miles.

Of the 88 yachts that started the race, 77 were still racing when the leaders crossed the line; 11 were forced to withdraw with gear failures or because of injuries to crew members.

The most high-profile casualty was the supermaxi Wild Thing, the 2003 line honors winner, which withdrew on Tuesday with sail damage when running in third place. Wild Thing's withdrawal ensured a a two-boat contest between Wild Oats and Investec Loyal, which were then well clear of their nearest rivals.

The 63-foot Reichel/Pugh-designed Loki continued to vie for overall handicap honors on Wednesday, despite a collision. Navigator Michael Bellingham said the Loki crew at first thought they had hit a sunfish.

"It was a very big object though, possibly even a shark or maybe a small whale, but it certainly stopped us," Bellingham said. "It took a little while to get him off, that's why we're not sure if it was a sunfish.

"I'm probably leaning more toward a shark or maybe a small whale or something of that kind."