London - A fire which largely destroyed the Cutty Sark, one of London's best-loved landmarks, was caused by an industrial vacuum cleaner which was accidentally left on for two days, police said Tuesday.

The famous 19th century tea clipper went up in flames in May, 2007, while it was undergoing major restoration work in dry docks in Greenwich, south-east London.

The blaze burned through each of the ship's three decks, destroying all the building work structures and tools on board and causing damage of an estimated 10 million pounds (18 million dollars).

Metropolitan Police investigators said the vacuum cleaner, used to remove waste from the ship as part of the renovation programme, had been left running throughout the weekend before the fire broke out on May 21, 2007.

The damage could have been far worse, however, as the ship's masts, deckhouses and saloon, along with half of its planking, had been taken away for conservation or storage.

According to Richard Doughty, chief executive of the Cutty Sark Trust, the blaze had increased the total conservation bill to
35 million pounds and set work back by at least two years.

Visitors and sightseers would be able to return to the ship by early 2010, he said. (dpa)