David Nalbandian is the subject of a police investigation in to an alleged assault against the tennis star at Queen's Club on Sunday.
The Argentine kicked out in frustration against an advertising hoarding after he had been broken in the second set, only for the hoarding to crash into the shin of a line judge Andrew McDougall, who was left with a bloodied shin.
Scotland Yard said a complaint had been made following an incident at the Aegon Championships yesterday.
A spokesman said: "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."
Nalbandian, who won the first set 7-6 following a tie break, was disqualified on a "code violation" as Croat Marin Cilic was named winner in the annual warm-up to Wimbledon.
The 30-year-old also had his £36,500 prize money withdrawn and could also be hit with a £6,400 fine.
He does however hope to return to the tournament in 2013.
"This incident doesn't mean that I'm not going to come back," said the Argentinian.
"It doesn't matter. I really feel good at this tournament. The tournament director is great to me and I like it.
"This is a bad situation for everybody and I really apologise for that but it doesn't mean anything to next year."