The Home Office has come under attack for attempting to justify its proposals to force Communications Service Providers to keep communications data for a year by falsifying a case study.

A Home Office document outlining the plans said that the rescue of a student lost on a foggy moor in the Western Isles would not have been possible without mobile telephone data which identified where he was.

It stated as a fact: “The use of telephone communications data was essential to finding this man, without which coast-guards would not have been able to approximate his location and save his life.”

But a local newspaper report at the time said the 23 year old student and his dog were rescued when he heard a helicopter nearby, pointed his mobile camera towards the sky and pressed the flash button several times.

A coastguard spokeswoman was reported as saying: “The helicopter crew were able to see the man on infrared after seeing the flashes.”

The Home Office has since presented a statement from the Marine and Coastguard Agency defending the blunder. It said that although the casualty attracted the helicopter with his flash, "his mobile data did aid his rescue."

This defence is questionable, since it took 14 hours for a helicopter to find him even though the telephone mast had been able to give a rough indication of his location following a phone call made by the student. He telephoned the coastguard and said he was lost on the moor before his phone lost power.

Western Isles SNP MP Angus MacNeil said he would raise the accuracy of the document with Home Secretary Alan Johnson.

He said: "This is the Home Office looking for 'intelligence' to justify its plans just as the government did [when it went looking for weapons of mass distruction] in Iraq. I hope the Home Office will think again about their reckless proposals for a Stazi-like society."