Shafilea Ahmed, 16, was allegedly murdered at her home in Warrington, Cheshire, because her parents felt her increasingly Western ways, and her rejection of an arranged marriage, had brought shame on the family.

Her younger sister, Alesha, was 15 when, she claimed, she had witnessed the killing on the night in September 2003 that Shafilea disappeared.

She initially told friends that her father, Iftikhar Ahmed, had murdered her sister and "chopped up" her body.

She later retracted the claim and kept silent for the next seven years. In August 2010 she gave detectives a detailed account of the murder and her parents' efforts to conceal the body.

Iftikhar Ahmed, 52, and Farzana, 49, now deny the murder.

Prosecutor Andrew Edis told the Chester Crown Court: "Alesha describes what is an act of suffocation by her parents, acting together - a carrier bag forced into her mouth and then hands over her face to close her airways so she could not breathe.

"She gives a description of what she saw, about what effect that had on her sister.

"She then describes how there was activity in the house that night to do with the body. She talks about looking into the kitchen and seeing her mother sorting through a pile of blankets and sheets. She saw a roll of black bin bags and two rolls of tape.

"She looked out of the window and saw her father with a large object wrapped in bin bags with brown tape wrapped around it."

Edis said Alesha gave her "bombshell" account in August 2010, a few days after being arrested in connection with a robbery at her parents' home.

She had pleaded guilty to robbery and was awaiting sentence.