Former prince Andrew Mountbatten-Windsor is back in the crosshairs of police in England ... he's under investigation for an alleged encounter back in the day with a woman at Royal Ascot. Cops across the pond are reportedly looking into an alleged incident from 2002 at the famous racing festival ... with police "examining events in 2002 as they consider wider possible crimes by Andrew Mountbatten-Windsor, including sexual misconduct, corruption and fraud" ... according to The Sunday Times .