The programme at fault was used to streamline and structure telephone data to make it accessible, and affects cases stretching over a seven-year timespan.

“When we speak about telephone information, we mean historical information on individual telephones, but also broader telephone information [regarding, for example, who was in a location at a certain time, ed.]. Both areas can be affected by this error,” said Torben Mølgaard Jensen, chief superintendent with the National Police (Rigspolitiet).

The issue was caused by the programming removing data it should have retained.

Police are able to pull data from telephone companies in connection with investigations of crimes, enabling them to see which telephones were registered by certain phone masts at specified times.

But the faulty programme may have deleted numbers from data pulled by police.

“We now have to check cases from 2012 to 2019, and these may be cases which are unsolved, and data may become available which wasn’t there before,” Jensen said.

“But there may also be cases in which convictions have been made, or where a complaint was made but no charge brought,” he continued.

The issue could, in a worst-case scenario, have led to wrong convictions, lawyer Kristian Mølgaard, who is chairperson of the National Society of Defence Lawyers (Landsforeningen af Forsvarsadvokater), told Ritzau.

“If there is missing data, that could mean a missing GPS location. And that GPS location could potentially be crucial,” Mølgaard said.

Both police and state prosecution authorities will now review potentially affected cases from 2012-2019, Jensen confirmed.

Up to 10,000 cases must be reviewed, the chief superintendent said.

“Until we have been through them all, we cannot say anything about how many contain errors, or how many errors influence (the case),” he said.

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