My mail has been tampered with, says Ferguson's son

In a new twist to the dispute between Sir Alex Ferguson and two of Manchester United's biggest shareholders, police are investigating claims of tampering with mail and rubbish at the home of the manager's son.

Cheshire police confirmed yesterday that they were examining a complaint by Jason Ferguson, a football agent, who has been accused by the Irish racing tycoons John Magnier, a former friend of Sir Alex, and J P McManus of profiteering from transfers authorised by his father. The shareholders have employed a private detective agency, Kroll Associates, to investigate Sir Alex and his son.

Mr Ferguson, who lives near Wilmslow in Cheshire, has alleged he has had mail and rubbish stolen and that a "suspicious person" has been seen near his home.

Sir Alex is in a legal dispute with Mr Magnier over the racehorse Rock of Gibraltar, which is now worth up to £200m through its stud rights. Sir Alex claims he is half-owner.