A TEENAGE robber who held a replica gun to the head of a Hayes postal worker has been convicted at the Old Bailey.

Gunman Michael Delopp, aged 19, faces prison after robbing two post offices in the space of three hours on October 5 last year.

The stocking-masked teenager was snared after PC Simon Dawes decided to carry out an unofficial surveillance operation on an address linked to the getaway car.

Delopp and an unknown accomplice first attacked Jayesh Patel's Post Office in Mitcham, in Surrey.

He threatened to shoot Mr Patel with the imitation gun, but the two ran off with no money when Mr Patel hit the alarm.

Delopp, of Thornton Heath, south-east London, then drove seven miles to Robert Radford's Post Office, in Hayes Street, Hayes.

Prosecutor Alan Bayliss said: “The gunman went up to assistant Maureen Short and put the gun against her head.

“Mr Radford gave them the notes from the till.”

Delopp made off in a car with £3,000, but a witness passed on the registration number to police and PC Dawes linked the car to an address in Croydon.

Mr Bayliss: “On his way home, Dawes decided to carry out an investigation and surveillance despite being off duty.”

He found Delopp with a bag containing the imitation Beratta 92 gun, clothes described by one witness at the crime scene and a pair of tights.

Delopp asked the officer: “Who tipped you off?”

He was found guilty on four counts of robbery, attempted robbery, and possession of an imitation firearm with intent to commit an offence.

Delopp had a number previous convictions for burglary, possession of cannabis and obtaining property by deception.

He is due to be sentenced on March 30.