The RSPCA said the prank would have caused the sheep "great stress"
The RSPCA has hit out at pranksters who put a live sheep in a shopping trolley and wheeled it into a supermarket in south-east London.
Two youths were recorded on CCTV carrying out the prank in Bexleyheath just after 0300 GMT on Friday.
Staff at the Asda store have named the animal Rob. It is thought to have been rustled from a farm near Gravesend in Kent.
The RSPCA said it was a "stupid, irresponsible stunt".
Joe Lock, manager of the store, said: "We were shocked to discover that a poor sheep had been wheeled into our store."
RSPCA inspector Andrew Kirby, who is investigating the incident, said: "We have tracked down the sheep's owner but we can't return it to its flock for six days because of restrictions on the movement of livestock.
"This stupid, irresponsible stunt would have terrified this poor sheep and caused it great stress by removing it from its flock."
The sheep was not physically harmed.
The maximum sentence for the crime of causing an animal unnecessary suffering is six months in prison and a £5,000 fine.