LONDON -- Officials on Friday were investigating suspicious betting

patterns on a match involving top-seeded Nikolay Davydenko of

Russia, who retired with an injury against a low-ranked opponent at

an ATP tournament in Poland.

In an unprecedented move, British online gambling company

Betfair voided all bets Friday placed on Thursday's second-round

match at the Prokom Open in Sopot between the defending champion

and No. 4-ranked Davydenko and No. 87-ranked Martin Vassallo Arguello of Argentina.

Betfair said it received about $7 million in bets on the match --

10 times the usual amount -- and most of the money was on Arguello

to win, even after Davydenko won the first set 6-2.

"You try to leave it to the players to play the game the right

way," said Andy Roddick, ranked fifth in the world. "I think we

expect that of them. If something's found that's shady, I, for one,

will be extremely [ticked] off.

"Obviously you want to wait and see it play out, but it's too

bad that it only takes one idiot to ruin things and create a bad

story."