A couple "unwittingly" hid the dismembered body of murdered British teenager Becky Watts in their garden shed believing it was drugs or stolen property, a court has been told.

Karl Demetrius, 30, and Jaydene Parsons, 23, had been "motivated by money", said the prosecution.

The pair admitted a charge of assisting Nathan Matthews after he killed his stepsister last year.

Demetrius' defence lawyer said his client had been in custody for 11 months for a "dreadful mistake", while Parsons' legal representative said "never in her wildest nightmares" had she imagined they had concealed body parts.

Matthews, a former TA soldier, suffocated 16-year-old Becky, at her home in Crown Hill, Bristol, while kidnapping her with his girlfriend Shauna Hoare, 21, on 19 February.

Four days later, Demetrius and Parsons agreed to hide bags and a storage box in a shed at their nearby home for Matthews.

He promised them a share of £10,000 (€13,000) to take the items.

But unknown to the couple, Matthews and Hoare had dismembered Becky's body in their bath and packed it into the bags and box.

Officers found Becky's remains in the locked shed on 3 March after Matthews confessed to killing her.

Matthews was jailed for life for Becky's murder, while Hoare was sentenced to 17 years in prison for her manslaughter, following a trial last year.

Demetrius and Parsons will be sentenced at Bristol Crown Court on Friday.

Prosecuting, Richard Posner said the couple "unwittingly" agreed to hide Becky's remains thinking they were drugs or stolen property.

He said: "They were motivated by money.

"They knew what they were doing was assisting Mr Matthews.

"Their actions contributed to the delay in finding Rebecca. Their actions certainly didn't mean that she would have been found alive."

Text messages and phone calls between Parsons and Demetrius revealed an agreement to hide the items for cash.

Parsons messaged her boyfriend "ah ok you guna hide it for him? we could do with the money lol xxxx", later adding "cool that's a deposit on a house lol".

Timothy Rose, representing Demetrius, said: "He wasn't expecting any of this to happen.

"He didn't know what was actually going on. He made what amounts to a dreadful judgement, a dreadful mistake."

Mr Rose said his client would require police protection after release from prison and apologised to Becky's family on his behalf.

Anna Vigars, for Parsons, said her client had been forced to leave Bristol because the "hatred" for what Matthews and Hoare had done had also been directed at the mother of two for her part in the case.

She said: "Never in her wildest nightmares did she imagine or contemplate that it was the body of Rebecca Watts that was being hidden in their shed."

Mrs Vigars apologised to Becky's family on behalf of her client.

Parsons was released on bail while Demetrius was remanded in custody ahead of sentencing.