SINGAPORE (AP) _ Four years after bringing down Britain's oldest commercial bank, rogue trader Nick Leeson was released from prison Saturday, but a London court has already imposed tight controls on his lifestyle.

Leeson, 32, left Singapore's Tanah Merah prison late Saturday night.

``He has left the prison, and been handed over to the immigration authorities,'' prison spokeswoman Geraldine Tan told The Associated Press. She declined to reveal his whereabouts.

The former futures trader was expected to fly home to London the same night, after three and a half years behind bars for fraudulently hiding $1.4 billion in losses.