Nine-month-old Areni Manuelyan died in July last year of bronchopneumonia brought on by malnutrition, weighing just two-thirds of her expected weight at 5.2kg (about 11lb).

Her parents had been feeding her on tomato juice and water and ignored a doctor's warning that she was terminally ill the day before her death.

Her mother Hasmik and father Garabet, both 45, of Staines, Surrey, pleaded guilty to child cruelty by gross negligence at a hearing in July. The crown prosecution service allowed a charge of manslaughter to lie on file.

"This is a most unusual and tragic case, perhaps even unique," Judge David Paget QC told the couple as he sentenced them to three-year community rehabilitation orders. "Your real punishment is that you will have to spend the rest of your lives in the knowledge that your stubbornness caused Areni's death. For loving parents like you that is a crushing burden to bear.

"In addition, your two eldest children have been taken away causing misery for them and you and your marriage has come to an end."

Doctors and dieticians had repeatedly urged the Manuelyans to widen the family's diets, but they insisted that they had to "follow the law of nature".

Mrs Manuelyan's previous health problems and an underlying low level mental disorder had resulted in an "obsession" with eating only organic raw vegan food, said Linda Strodwick, defending.

Their two elder children, a nine-year-old boy and six-year-old girl, were placed on the child protection register in 1996 because of concerns about their health, but the Manuelyans moved first to Armenia, where they both grew up, and then to France.

Areni was born shortly after their return to Britain in 1999. But she developed slowly and her health deteriorated dramatically when the family went to live in a vegan commune in Spain.

In July last year they returned to the UK to get medical help, taking Areni to a private practitioner for oxygen treatment. He told them she would die without immediate intravenous feeding and they said they would think about it. By the following morning, she was dead.

The Manuelyans are to separate and their children are living with foster parents while care proceedings continue.

The couple were too upset to comment yesterday. Earlier in the week Mr Manuelyan, who gave up his job as a bus driver following his daughter's death, said the events were "a terrible trauma for us, like a bad dream."