LEON ROBERTS cuts a menacing figure at night: his arms are heavily tattooed and his eyes stare from under his baseball cap.

However, it is a sight which should not be troubling the people of Long Eaton, near Nottingham, because since October Roberts has been wearing an electronic tag and has been barred from leaving his flat between 8pm and 6am.

Roberts was given the curfew order on his conviction of a violent assault. He will not talk about precisely what he did, but he is slightly more forthcoming about a previous conviction last year for affray (“It was just for fighting in the street”) and his 2002 conviction for unlawful wounding when he took a bottle to the head of a “friend”.

He admits that he contravened the terms of his curfew: a few days after his conviction he stayed out drinking, having “forgotten” about his tag.

What surprised him, however, was the behaviour of the people meant to be monitoring his movements. “When I got back they rang me and said they weren’t picking me up. I said I was there and they said the equipment must be faulty and they would send someone round to check it. But they never did.”

Although Roberts does not admit to any other violations of his curfew, records obtained by this newspaper show that by December 14 he had accrued more than the four hours which constitutes a breach of his curfew under Home Office rules.

Under these, this violation should have been dealt with within 24 hours of being confirmed. But he claims that it was nearer a week before any contact was made. “When they did, I signed a statement saying I had been here. Then I got a letter three weeks ago saying any further late times and I would be taken back to court. I threw the letter away.”

An internal document from Group 4 Securicor, the company responsible for overseeing much of the government’s tagging regime, shows that Roberts’s case is one of hundreds in which tagged offenders have roamed free, posing a potential threat to the public.

The 21-page document, from Group 4 Securicor’s monitoring centre for the East Midlands, details 599 tagged offenders who had accumulated time violations of their curfews. They represent two-thirds of all those tagged in the region.

Three years ago a failure in the tagging system in Nottingham enabled Peter Williams, a teenage offender who ignored his curfew, to murder Marian Bates, a jeweller. Group 4 was not in charge at the time.

Harry Fletcher, assistant general secretary of the National Association of Probation Officers, said lapses were occurring nationally: “There are delays in tags being fitted and offenders are not being properly monitored. We have seen examples of people violating their curfews 20 or 30 times.”

Home Office rules state that violations of less than two hours can be ignored, but anything more must result in a warning in the first case and, if repeated, lead to “breach” proceedings. Offenders are either jailed or re-tagged.

However, according to a whistleblower who has given a detailed account of practices at the Nottingham-based monitoring centre, procedures are being flouted because of a lack of trained staff.

“There will be maybe eight or so new violations each day but they stack up on the computer because processing them takes so long. The offenders know that near the end of their tagging terms they can ignore the curfews because court proceedings are rarely pursued.”

Offenders who appear on the list, dated December 14, 2005, confirmed that there had been poor supervision.

Rebecca Barker, 27, who was convicted of assault, admitted staying out until the early hours and on her return she was told she was to be held in breach. “They started court proceedings but my tag came off on December 23 and now they seem to have forgotten about it,” she said.

Simon Cattell, an unemployed 21-year-old from Leicester, was arrested earlier this month after breaching his curfew by more than 120 hours. According to Julie, his mother, it took staff from Group 4 a week to respond and it was a month before the police took action.

Equipment failures are a common story. Nicky Barr, 16, from Broxtowe in Nottingham, was tagged five months ago by the firm when he received an anti-social behaviour order. The tag attached to Barr, who was identified during legal proceedings, is supposed to record any violations of his 7pm to 9am curfew. But staff monitoring his tag have turned up three times at his mother’s door believing he had taken his tag off, only to find it had failed.

The whistleblower said: “Staff are taking days and sometimes weeks to catch up with the workload and in the meantime offenders are able to run up large tallies of violations.”

Group 4 Securicor said it had acted appropriately except in a minority of cases. It denied that temporary staff were being asked to take important decisions and insisted that 99.5% of offenders were tagged within 24 hours of starting the curfew order. “The Home Office applies rigorous audits of our service,” said a spokesman.

The firm has been one of the main commercial beneficiaries of the government’s increasing reliance on tagging. Last April it snatched the contract for the East Midlands from Premier, a competitor, and became the single largest provider of curfew orders with 8,000 offenders under its supervision.

Of the 11,667 offenders tagged nationally at the end of last year, 6,949 had been given curfews as part of community sentences for crimes considered minor by the courts, including assault, burglary and theft. A further 1,069 were on bail, while 3,649 were on early release from prison sentences.

A National Audit Office report into the system, to be published this week, is understood to be concerned about long delays in fitting convicted offenders with tags and in bringing transgressors back to court.

Additional reporting: Steven Swinford

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