FAMILY members who kept a vulnerable man as their slave over many years, then killed him, cut up his body and dumped it in the Blue Lagoon at Arlesey, have today (Friday) been convicted of murder and familial homicide. The ringleader was said to be James

FAMILY members who kept a vulnerable man as their slave over many years, then killed him, cut up his body and dumped it in the Blue Lagoon at Arlesey, have today (Friday) been convicted of murder and familial homicide.

The ringleader was said to be James Watt, 27, who ordered others in the family to repeatedly assault Michael Gilbert, 25, at a house in Luton where the extended Watt family lived.

The victim was beaten and assaulted for fun, and often the assaults were recorded on mobile phones for amusement.

He was shot at with an air rifle, had mole grips applied to his testicles, and his pubic hair set alight. He slept on the floor handcuffed to a bed to prevent him escaping. Twice he did get away but was tracked down by the family and brought back to Luton. They kept his benefit money, giving him a pouch of tobacco a week.

As his ordeal went on the violence increased and by the end of 2008 people were doing press ups on a piece of wood across his mouth, and jumping on his stomach.

One of those who jumped on him was Nicola Roberts, 22, who weighed 21 stone at the time, Luton Crown Court was told.

After that Michael's health deteriorated, but no one in the household sought help for him, even though he was losing control of his bowels, and was physically pale and in pain, said prosecutor Stuart Trimmer QC.

He died at the house in Marlborough Road, Luton on January 21 last year. The same day his body dismembered at the house and his head was cut off.

The parts were put in two plastic sacks, weighted down with coping stones from the garden wall, and driven to the Blue Lagoon, a well known beauty spot.

One bag was found in May last year, but the head was not recovered until February this year after one of the Watt brother's Richard, 25, confessed to police what had been happening in the house. He gave evidence for the prosecution.

Today, James Watt, his girlfriend Natasha Oldfield, 29, and Nicola Roberts were all convicted of Michael's murder.

Robert Watts, 20, and Jennifer Smith-Dennis, 58, the mother of all the Watt brothers were both convicted of familial homicide - also known as causing or allowing the death of a vulnerable adult.

Her partner and the brother's father, Antonio Watt, 70, was cleared of the only charge he faced, conspiracy to pervert the course of justice by misleading police about the last time they had seen Michael alive.

Natasha Oldfield and Jennifer Smith-Dennis were also convicted of conspiracy to pervert the course of justice by disposing of the body. James Watt, Richard Watt and Robert Watt had pleaded guilty to that offence.

Nichola Roberts and Jennifer Smith-Dennis were convicted of conspiracy to pervert the course of justice by lying to police and Natasha Oldfield was convicted of assisting an offender by booking a hotel room for James Watt.

They will all be sentenced on Monday.

The jury of six men and six women reached their unanimous verdicts after deliberating for 26 hours. Judge John Bevan QC said they had had to listen to 'ghastly' evidence and said they need never serve on another jury in their lifetime.

After the verdicts Michael's mother Rosalie White, 49, said: "This is justice for Michael.