Low-key, Aberdeen-based Tommy Dreelan and his brothers Sean and Ciaran - all from Ferns, Co Wexford - made over €180m in previous years from selling two oil services and engineering companies, Qserv and PSL. They are big fans of cars and motor racing, with Tommy heading up the Celtic Speed team, with which he's raced Porsche 911s. The team also owns classic F1 and Le Mans cars. Tommy and his co-driver achieved third place in a Daytona classic race in the US late last year.
He and his wife bought a Ballsbridge penthouse apartment in 2012, and there is believed to be other property owned by the family.