Singer Pete Doherty protested his innocence after being questioned by police following a drugs raid in the town where his band had been playing.
Doherty said his overnight detention had been "some sort of mistake"
The Babyshambles frontman claimed police had mistaken an implant aimed at keeping him off drugs for "hard stuff".
As he walked out of a Shropshire police station on Sunday Doherty, on-off boyfriend of troubled supermodel Kate Moss, labelled the law "a pain".
His band had been playing at Shrewsbury's Music Hall on Saturday.
The venue was raided by drug squad officers with sniffer dogs in the early hours of Sunday.
Police said a man and a woman were later arrested for possession of class A drugs.
Seventeen people were searched during an operation in various parts of the town.
Doherty was taken to Telford police station and detained for more than 12 hours before being bailed to return in December.
Speaking to reporters outside the police station, he said: "It's just some sort of mistake, that's all."
He then showed photographers what he claimed was an implant in his lower abdomen.
The woman arrested was questioned but later released without charge.
A spokesman for Doherty earlier said: "I can confirm that he was detained and held overnight, although I have no details of the exact circumstances."
Two coaches were also searched in the town and suspected drugs seized.
A spokesman for West Mercia Police said: "In the early hours of this morning officers stopped a mini bus in Shrewsbury town centre and detained a number of people for the purposes of a drugs search.
"A number of items have been recovered and these will be subjected to forensic examination in due course."
A gig in Norwich planned by Babyshambles for Sunday night has been cancelled.