Despite his 158 court appearances, the authorities were powerless to detain him at the age of 11.

You have previously committed offences which could have been punished with prison terms - we have got to protect the public from the risk of serious harm

Clive Williams, magistrates chairman

Cardiff magistrates sent him to a secure unit on Wednesday to "protect the public from serious harm" after he was charged with burglary at an industrial site.

The boy - who cannot be named for legal reasons - has already prompted a pledge from Home Secretary David Blunkett to tighten up the law to put children under the age of 12 into care if they persistently offend.

The latest incident related to a break-in at Freshmoor Road, Cardiff on 27 May - just 17 days after the boy's 12th birthday.

Prosecutor Paul McGann said: "Police were called to deal with intruders to the site.

David Blunkett pledged tougher action

"Windows had been damaged and shutters removed, and wires to the intruder alarms were cut."

The court was told the boy was one of six youths found by police inside a portable building at the scene.

He denied burglary but was refused bail.

Magistrates chairman Clive Williams told the boy: "You have previously committed offences which could have been punished with prison terms.

"We have got to protect the public from the risk of serious harm."

He was remanded to a secure accommodation unit until a trial starting on 17 July.

Last month, just days before his birthday on 10 May, he was sentenced to a three-year supervision order at Cardiff Youth Court.

The boy was a serial car thief

It followed what Judge Gerwyn Watkins called "an appalling catalogue of offences".

He said it was remarkable that no-one had been injured following a string of car thefts.

The judge added that the boy would have been detained had he been 12 years old.

His parents had urged the authorities to help because they could not control the boy.

The youngster had recently been living with foster parents in the south Wales valleys.

He was said to have made some improvement in his attitude to crime before his latest court appearance.