Two suspected thieves were arrested when they walked into a pub where police were holding their Christmas party.
While celebrating in south London on Wednesday, off-duty officers noticed two men behaving suspiciously, who appeared to fit the descriptions of suspects following a spate of bag thefts in the area.
Pc Lucy Blackmore, Sergeant Richard Cloke and community support officer Craig Mulgrew detained the men and called for back-up at The Merchant pub, in Battersea Rise, a Metropolitan Police spokesman said.
Chief Inspector Charlotte Taylor, of Wandsworth Borough Police, said: "I am delighted that my officers acted in this positive way, particularly at this time of year when this type of crime causes considerable distress to victims.
"Their actions show police officers are never off duty and always willing to intervene when they suspect crimes are being committed."
It followed a spate of incidents in the area, where thieves placed magazines on tables over a victim's property and then removed both items at the same time.
Two 19-year-old men were arrested on suspicion of going equipped to steal and were bailed to return next month, police said.