The actor who played PC Reg Hollis in the TV series The Bill has helped real-life police officers arrest a shoplifter who was trying to escape on a bicycle.

Jeff Stewart, who played Hollis for 24 years in the long-running ITV drama, sat on the suspect’s legs while officers handcuffed him after he had fallen off the bike in Southampton, Hampshire, on Wednesday.

Mohamed Diallo, 29, of Southampton, was charged with five counts of theft, to which he pleaded guilty at Southampton magistrates court on Thursday. He was bailed to be sentenced on 29 August.

A Hampshire constabulary spokesperson said: “In policing you should always expect the unexpected, but this really wasn’t on The Bill for this week. Officers making an arrest in Southampton were aided by none other than TV’s PC Reg Hollis during an incident on Wednesday 23 July.”

The spokesperson said “officers pounced to make their arrest” of Diallo after he fell off the bike while trying to escape. “To their surprise, local TV legend Jeff Stewart … came to their aid by sitting on the suspect’s legs while officers put him in cuffs.

“Long since retired from Sun Hill station – but he’s still got it.”

Diallo was convicted of the theft of £17.25 worth of coffee from a Co-op on 23 July, the theft of £69.90 worth of coffee and food items on 17 July, and of £54.50 of alcohol and coffee on 14 July. He also admitted stealing £80 of wine from a Sainsbury’s on 14 July and £63 of alcohol on 22 April.

The Bill, which ran from 1984 until 2010, followed the professional and personal lives of officers and detectives from the fictional Sun Hill area of east London.