The 30-year-old was defaulted from the Queen's Club final in west London on Sunday for angrily kicking an advertising board at line judge Andrew McDougall which left the official suffering a gashed and bloodied leg.

Scotland Yard said Monday: "We are aware of an incident at the Aegon Championships on June 17. A complaint has been made and the Metropolitan Police Service is now investigating.

"The allegation is of assault."

There was more bad news for Nalbandian, who had already been stripped of his 44,945 euros ($56,802) runners-up cheque and 150 ATP ranking points, when he learned the ATP had fined him 10,000 euros ($12,566), the maximum punishment allowed for his conduct.

"Nalbandian automatically forfeited his prize money and ranking points due to his conduct default," an ATP spokeswoman said.

"A maximum 10,000 euro fine also was issued onsite by the ATP Supervisor for unsportsmanlike conduct."

He could also face an eight-week ban having also been fined $8,000 for throwing water at an Australian Open tournament worker in January following a five-set defeat by America's John Isner.

Nalbandian, who had won Sunday's first set 7-6 (7/3) against Croatia's Marin Cilic, had just lost his serve to fall 4-3 down in the second when he reacted with a frustrated kick at the board, which was just in front of McDougall.

A stunned and angry McDougall then rolled up his trousers to reveal a bloody gash on his leg before remonstrating with Nalbandian.

Officials immediately disqualified Nalbandian "due to unsportsmanike behaviour" and Cilic was declared the champion of the ATP grasscourt event, a warm-up for Wimbledon.

Having already apologised on court for his actions, Nalbandian issued a further statement through the ATP late Sunday in an effort to limit the damage ahead of Wimbledon, where he was runner-up in the 2002 men's singles final.

"I never intended to hit him (the line judge), it was an unfortunate reaction in which I wanted to let off steam after losing a point," Nalbandian said.

"I had the opportunity to personally apologise to the line umpire for this regrettable act that I am fully responsible for."

Although Nalbandian was contrite about the actual incident, he also vented his frustrations at the ATP.

He claimed officials impose too many rules on players, including asking them to play in the kind of slippery conditions that have been commonplace over the last few days at Queen's.

Nalbandian risked getting in more trouble as he said: "Everybody makes mistakes, right? When somebody else does a mistake, they have to pay in the same way, but the players don't feel that happens much, especially with ATP.

 "Sometimes the ATP put a lot of pressure on the players, and sometimes you get injured because you play on dangerous surface and nothing happens."