Bookmaker William Hill has started paying out on bets for Dame Helen Mirren to win the best actress Oscar - five days before the awards ceremony.
The firm will settle bets worth £50,000 after Dame Helen's odds reached 1/66.
A William Hill spokesman said: "Should the unimaginable occur and Dame Helen fails to win the Oscar, then she will have been robbed and so will we."
Other bookmakers including Ladbrokes and Paddy Power are still taking bets on Dame Helen ahead of Sunday's awards.
But they agreed she was the strongest ever Oscar favourite.
William Hill made Meryl Streep a distant second favourite to win best actress, at 12/1 for The Devil Wears Prada.
It is the first time in over 20 years of Oscar betting the bookmaker has paid out before the ceremony, the bookmaker said.
William Hill spokesman Rupert Adams explained: "We have not taken this decision lightly, but it has been one-way traffic since we opened the betting, with almost every penny accepted on the best actress market for Dame Helen.
"It has got to the stage where we just don't want to take any more. Dame Helen has swept the board at all the major awards and looks a certainty to walk away with the Oscar."
But Paddy Power spokesman Darren Haines said: "There are still people betting on the other contenders and the Oscars have a habit of pulling at least one surprise."
Across the board, Forest Whitaker is favourite to win best actor, with crime thriller The Departed leading the pack for best film.