Kidnappers released former Prime Minister Paul Vanden Boeynants and he returned home "safe and sound" Tuesday after a month in captivity, the Justice Ministry said.

Unconfirmed reports said the family of Vanden Boeynants, a wealthy businessman, paid a ransom of as much as $5.1 million.The 69-year-old Christian Democrat was freed late Monday near the railway station in Tournai and took a cab to his Brussels home 50 miles away, said Brussels deputy prosecutor Andre Vandoren.

There was no immediate explanation of where or under what conditions he had spent the month.

Investigators said they questioned Vanden Boeynants, whose career has been tainted by scandal, and were satisfied he had been kidnapped.