A plan to require registered sex offenders to notify police of their email addresses and social networking identities has been shelved while the government battles a human rights judgment in the High Court, according to the Home Office.

The measure was the centrepiece of a suite of announcements on child protection on and offline in early April last year, but no detailed proposals have since emerged.

At the time Jacqui Smith said failure by the more than 30,000 registered sex offenders to supply online identities or supplying false identities would attract up to a five year jail term. "We need to patrol the internet to keep predators away from children in the same way as we patrol the real world," she told the breakfast television show GMTV.

However, in December the High Court found that indefinitely retaining details on the Sex Offenders Register with no right to appeal was a breach of offenders' human rights under European law.

A Home Office spokesman said officals had decided not to try to extend the reach of the sex offenders register online while government lawyers appeal that decision. He said the case had "an impact" on notification requirements, but was not able to explain how.

Other planned changes to the register, such as a trial of "Sarah's Law" allowing parents to demand details of sex offenders, have gone ahead.

The NSPCC, which supported plans to monitor internet use by sex offenders, said it had not heard of any developments. "It's hard to comment as we don't know enough about where this email register idea has got to," a spokesman said.

The policy was heavily criticised when it was announced by internet experts, who said the profusion of free email and social networking services and the simplicity of setting up new accounts would make it unworkable.

The Home Office said the government remains committed to collecting sex offender email addresses and social networking identities, which was first mooted by then-Home Secretary John Reid in February 2007. Last year it said the details of monitoring sex offenders' online identities would be handled by the Child Exploitation and Online Protection Centre (CEOP).

CEOP declined to comment on progress, saying policy announcements were a matter for the Home Office. ®