A woman has been found guilty of being at the centre of a paedophile ring which set children up as "sexual play-things" over more than a decade.

Ten seemingly respectable people - including six women - were on trial accused of the abuse of five children which is said to have centred around Marie Black, 34, from Norwich.

She denied 26 offences during a three-month trial at Norwich Crown Court. Today, after 19 hours of deliberations, the jury convicted her of all but three counts.

She was found guilty of offences including rape, conspiracy to rape and inciting a child to engage in sexual activity.

Black sobbed uncontrollably in the dock as the verdicts were delivered. She was heard saying: "I've been stitched up."

Michael Rogers, 53, from Romford, Essex, was found guilty of 14 counts including cruelty, rape and inciting a child to engage in sexual activity.

Jason Adams, 43, from Norwich, was found guilty of 13 similar counts.

Judge Nicholas Coleman remanded all three in custody until sentencing on September 28, saying: "These are very serious matters."

Carol Stadler, 59, from Norwich, was found guilty of assault causing actual bodily harm but cleared of nine other charges, including serious sexual assaults. She was released on bail.

Undated Norfolk Constabulary handout photo of (left to right) Carol Stadler, Michael Rogers and Jason Adams, who have been found guilty today off being part of a paedophile ring, led by Marie Black (PA)

The remaining defendants - Anthony Stadler, 63, Nicola Collins, 36, Andrew Collins, 52, Judith Fuller, 31, Denise Barnes, 43, and Kathleen Adams, 85, all from Norwich - were cleared of all counts.

Opening the trial, prosecutor Angela Rafferty QC said Black, previously known as Marie Adams, played an instrumental role in using the children as sexual play-things.

The abuse, which is said to have happened in and around Norwich and London, included forcing the children to have sex with one another.

On some occasions, the adults threw parties and played card games to decide who would abuse which child, Mrs Rafferty said.

In interviews the victims described how they were abused in front of one another and other adults. Some of the abuse involved children's toys, including Barbie dolls.

They said the abuse became so routine that the victims came to accept it as normal.

One of the male victims said: "There would be parties and they would do some games where the boys were in one room with the men and the girls were in another with the women.

"The adults would have a card game and the winner would get to choose a boy to start touching their private parts and then hurt them afterwards."

Describing Black, Mrs Rafferty said: "Was she a helpless victim of abusive males or was she herself deeply involved with the children's ill treatment?"

She added: "Many of the defendants have become good at appearing normal and respectable.

"This is what you would have to do in order to be child abusers to the extent alleged here."

All of the defendants denied abusing the children, saying it simply did not happen.

During the trial it emerged that police had launched an investigation in to the conduct of Norfolk County Council social workers involved in the case.

The court heard that the trial had originally been due to start last year only to be delayed when prosecutors raised concerns over changes made by social workers to statements taken from the children.

This resulted in Norfolk Police launching an investigation into alleged misconduct.

Sarah Elliott QC, representing Black, told the court that at the time the county's children's services department had recently failed an Ofsted inspection, being ranked "inadequate" in all areas.