A sock packed with Monopoly money triggered a full-scale bomb alert outside Lewes Prison.
A member of the public raised the alarm when he spotted the suspicious package at the entrance to the prison yesterday.
Bomb disposal teams were called in as police sealed off the road.
Traffic backed up along the busy Brighton Road for almost two hours as investigations continued and the device was made safe.
But when the package was blown up in a controlled explosion it was found to contain thousands of pounds - in toy notes.
Officers said a cup was also among the items, which had been stashed inside the abandoned garment.
A police spokesman said: "It is a mystery how it got there and who was behind it.
"It may only have been a sock but in this day and age you don't take chances."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article