Police say they are investigating an assault complaint filed against David Nalbandian after the Argentine tennis player kicked an advertising board and injured a line judge during the Queen's Club final.
London police declined to say who made the complaint against Nalbandian, who was defaulted from Sunday's match against Marin Cilic.
Any member of the public who witnessed the event in person or on television could have made a complaint, as could the line judge himself.
Nalbandian had been leading Cilic 7-6 (3), 3-4 when the incident occurred. After missing a running forehand, Nalbandian kicked the board under the male line judge's chair. A piece of the barrier cut the judge on the left shin, leaving him bloodied.
Tournament director Chris Kermode said the judge received first-aid care but needed no further treatment after seeing a doctor.