Police in Denmark began looking at the issue when they found a bug in software that converts data from mobile towers to render it useable by officers.

This, however, caused important information to be omitted.

If a phone made five calls within an hour, for example, the software would only account for four.

Other problems include the origin of texts being incorrectly registered and faulty information on the location of particular towers.

Following an audit in August, 32 people, who have either been convicted or are on remand, have been released.

“We simply can’t live with the idea that information that isn’t accurate can send people to jail,” Denmark’s chief public prosecutor Jan Reckendorff told public broadcaster DR.

A two-month halt on the use of such data as evidence in trials was announced in mid-August.

“This is a very drastic decision. But it is a decision that is necessary in a state of law,” Mr Reckendorff said.