Alisdair Dawson: "Good alternative to prison"

They were warned that leaving their homes during specified periods would set off an alarm and they risked being sent to jail.

Ministers have now started to investigate proposals to extend the scheme to people convicted of more serious offences.

Of the offenders who took part in the scheme, the report said only 28% failed to participate fully.

Sheriffs have supported the scheme, which they say gives them greater sentencing flexibility.

'Positive addition'

Deputy Justice Minister, Angus MacKay, said: "The sheriffs in those participating courts did find the orders a useful addition and they were confident that the monitoring equipment had worked satisfactorily.

"I think it's probably best to rely on the evidence of the sheriffs themselves who have been closest to the working of the system and basically satisfied that it was a positive addition."

Angus Mackay: "A useful addition"

John Scott, chairman of the Scottish Human Rights Centre, said the system was not a soft option.

He said: "The research tends to suggest that the offenders know that it's not something that's easy and, in fact, I think there has been at least one situation where the offender rang up and said 'take me to jail because this is doing my head in'."

And Alisdair Dawson, from Aberdeen's social work department, said: "The biggest worry with prisoners is that offenders are exposed to other offenders.

"As an alternative to prison it is welcome."

Last month, the executive faced a call for more sophisticated tagging techniques to be used for serious, violent and sex offenders.