Thousands of eyes and ears should have been alerted last night to keep a look-out for Summer within minutes of her disappearance.

But only the first stage of the Child Rescue Alert network pioneered by Sussex Police after the kidnap and murder of Sarah Payne three years ago this month was activated.

Police today admitted technical problems had hampered last night's first major test of the network. They promised a review but said they would probably carry on using it.

The Argus prompted the force to test the revolutionary scheme after the success of a similar project called Amber Alert, which operates in 15 American states and began in 1996. Police say it has helped save the lives of 36 children.

The first phase of the scheme sees television and radio programmes interrupted within minutes of the disappearance of a child.

The second phase - launched in Sussex last March - involved mobile phone users being sent crucial details of the kidnap, including descriptions of the child or their abductor.

Thousands of people signed up for the scheme, expected to be rolled out across the UK.

But questions were soon being raised about its operation when police failed to use the system to help hunt for missing toddler Merlin Reid.

Police said the criteria for the scheme had not been fulfilled because there was no evidence Merlin had been abducted. Their decision was later borne out by events.

The criteria includes the child being under 16, reasonable belief they have been abducted and their life is in danger and sufficient information to give to the public.

Text messages are sent out by East Grinstead company Community Alerts. It developed software which enables police to send messages to everyone registered within a specified area.