A woman and her partner brutally beat a New Addington man to death believing he had sold her sister cocaine, a court heard.

Cherri Gilmartin, 37, and Jason Lodge, 39, viciously attacked David Petch outside his home in Wayside, Fieldway on April 14 last year, prosecutors told the Old Bailey today.

The couple, who are both grandparents and have eight children together, beat him with a baseball bat before stamping on his head and leaving him to die, the court was told.

Mr Petch, 55, died four days later of severe head injuries.

Miss Gilmartin and Mr Lodge, long-term partners, of Uvedale Crescent, New Addington, whose trial began today, deny murder.

They are accused of carrying out the attack after thinking Mr Petch had sold cocaine to Miss Gilmartin's sister.

Prosecutor Simon Denison told the court: "Both these defendants played part in a wholly unlawful, vicious attack on Mr Petch that resulted in his death, and each is guilty of the offence of murder."

He added: "Even if Miss Gilmartin is right about Mr Petch supplying her sister with cocaine, it in no way justifies what she and Jason Lodge did to him."

Mr Denison told the court the alleged killers had been drunk and angry on the night Mr Petch died and had banged on his neighbours' doors looking for him.

Miss Gilmartin later told the police she had wanted to tell Mr Petch to stop selling cocaine to her sister, Laura Field, who had a history of drug abuse.

The court heard Mr Lodge and Miss Gilmartin had knocked at one neighbouring flat and yelled "open the f****** door" and "Where's Petchy?" while holding a beer can and wine bottle.

When another neighbour, John Nolan, asked them to be quiet, Mr Lodge is said to have said, "l'm going to sort out the fella down here," and pointed along the balcony of the block of flats.

Mr Denison told the court the couple then moved on to Mr Petch's first-floor flat shortly before 11.30pm and tried the door handle, finding it to be unlocked.

The court heard Tony Leigh, an ambulance technician who lived opposite Mr Petch's flat, saw the couple go inside and emerge minutes later with Mr Petch, who had been alone at home.

Prosecutors said Mr Leigh saw Mr Petch seemingly trying to push Mr Lodge out of his flat, whereupon Mr Lodge allegedly punched Mr Petch and shoved him up against a wall.

Miss Gilmartin is alleged to have then clubbed Mr Petch three or four times hard with a baseball bat, which is said to have been found in his flat.

Mr Leigh heard a crunch as the bat struck Mr Petch's head, the jury was told.

Mr Lodge allegedly then repeatedly stamped on Mr Petch's head as he lay on the ground.

Mr Denison said: "Mr Leigh saw him raise his leg and bring it down hard at least six times.

"He thought he was being kicked in the head and chest area. The kicks were deliberate and hard."

Mr Petch, who had nine children, was taken to Croydon University Hospital but died on April 18 after suffering bleeding on the brain caused by a fractured skull.

The court heard Mr Lodge and Miss Gilmartin, both unemployed, initially fled to Rye, Kent, but attended Croydon police station on April 17, when they were arrested.

Both deny murder.

The trial continues.