The inquiry centres around Wembley's hugely profitable operation in Lincoln Park, Rhode Island. Allegations were first made in May 2001 after Francis Sherman, Wembley USA's president, and David Brents, the chief financial officer, filed for wrongful dismissal. They said they were dismissed for refusing to take part in a scheme to pay money to an unnamed attorney over six years.
The dismissal claim was subsequently settled out of court last month, with Wembley paying an undisclosed sum to the two directors. But the Rhode Island attorney's office has launched a separate investigation into the allegation.
Wembley bought Lincoln Park, which includes a greyhound track and several hundred gaming machines, in 1990 for $60m (EUR69m). The company's US subsidiary also owns horse and greyhound tracks in Colarado.
Questions are also likely to be raised from the London Stock Exchange and shareholders about why it kept news of the investigation away from investors. The company reports full-year results on Monday.
