A shop assistant who fatally stabbed his best friend claims it was a “terrible accident” while he was preparing potatoes for dinner, the Old Bailey heard.

Ronny Padilla, 23, is accused of murdering 19-year-old Sabri Chibani at the home they shared in Streatham, plunging a kitchen knife into his chest.

Jurors heard Padilla stood “calmly” by as Mr Chibani lay bleeding to death. He later told police the stabbing had been an accident and that Mr Chibani had “rushed” into the knife.

William Emlyn Jones, prosecuting, said: “He described how he had a kitchen knife in his hand ready to prepare some potatoes … he had forgotten he kept them in his closet in his bedroom. Still holding the knife, he went to his bedroom to get two potatoes, and on his way back he passed Sabri who was ‘rushing or something’.”

The court heard that Padilla told police: “He came straight to me and I stab him for accident in the chest.”

The defendant claimed he was holding two potatoes and dropped them, but Mr Emlyn Jones told the jury “there aren’t any potatoes, not in his bedroom, not in his kitchen, not on the floor”.

The court heard Padilla, lived with “best friend” Mr Chibani and his brother Sadok, and a fourth man. On February 11, the day of the alleged murder, neighbours reported being “disturbed by loud voices” and a scream.

Padilla, of Streatham, denies murder. The trial continues.