Two pits are being excavated near the boy's dormitory at a former Jersey children's home where the remains of a child were found, police said yesterday.

The inquiry team at Haut de la Garenne, the home where more than 100 people claim they were abused, were contacted by a man claiming he was asked to dig the pits during the 1970s or 1980s.

The man told police that, when he asked what they were for, care staff told him "it was none of his concern". When he returned the following day he was ordered to fill in the pits.

A police spokeswoman said forensic teams have excavated one pit and are working on the second.

She said: "The team excavated the first pit and found it to be about 1.5 metres deep.

"At the bottom of the pit was a large quantity of lime. There was nothing else in the hole.

"The inquiry team can think of no reason why this pit would have been created, nor why it was filled with lime.

"We would emphasise that we have no evidence of any motive. We are currently excavating the second pit which is very close to what was the boys' dormitory."

Fragments of a child's skull were found under a stairwell at Haut de la Garenne in February.

The home is at the centre of one of Britain's biggest ever abuse investigations with more than 100 people claiming they were assaulted there since the 1960s.

Some of the victims claim they were kept in solitary confinement and attacked in secret underground chambers known as "punishment rooms".

There was a large quantity of lime found in the stairwell where the skull fragment was found.

The police said this meant they had no knowledge of how, when or where the person died.

Police have also found and excavated a network of four underground rooms. The police spokeswoman said: "The forensic examination of the third and fourth rooms of the cellars continues.

"A number of finds have been made and are being studied. They have the potential to further corroborate the versions of events given to us by victims who have come forward.

"It is expected that this work will continue into next week."

So far, only one man has been charged in connection with the abuse inquiry, which focuses on Haut de la Garenne but involves other care homes on Jersey.

Gordon Claude Wateridge is charged with three offences of indecent assault on girls under 16 between 1969 and 1979 when he was warder at the home.

The 76-year-old is on conditional bail and will next appear before St Helier Magistrates' Court on May 12.

There are more than 40 suspects in the inquiry as a whole.

Haut de la Garenne closed as a children's home in 1986.