Swedish ISP Bahnhof must resume retaining customer communications metadata for police use by the end of November or pay a fine of 5 million Swedish Kronor (US$685,000), the Swedish telecom authority has ruled.

Bahnhof should comply with Swedish law requiring ISPs to retain customers’ location and traffic metadata for six months for law enforcement purposes, the Swedish Post and Telecom Authority (PTS) said Monday.

Bahnhof will fight the order, CEO Jon Karlung said Tuesday.

The ISP stopped retaining the communications metadata and deleted all records with the permission of the authority after a May ruling by the Court of Justice of the European Union (CJEU) invalidated the EU’s Data Retention Directive because it seriously interfered with fundamental privacy rights.

The Swedish data retention law is based on that directive and the CJEU ruling was the reason the telecom authority allowed ISPs to stop collecting data and delete records without consequence. However, in August, after government pressure, the authority flip-flopped and ordered ISPs to start retaining data again.

Bahnhof refused, saying that the government and the authority could not just blatantly ignore a CJEU ruling. The ISP filed a complaint in September, asking the European Commission to intervene.

So far, there has been no word from the Commission aside from a confirmation that the complaint was received, Karlung said.

While the Commission may be in no hurry to respond, it does take the independence of regulatory authorities seriously. Earlier this month it took Belgium to court because it found the country could not guarantee the independence of its telecommunications regulator. EU rules forbid political interference with national telecom authorities, but in Belgium, the country’s Council of Ministers can suspend the regulator’s decisions.

Karlung meanwhile said he has a Plan B to deal with the data retention problem, which suggests he may have found a loophole allowing him to comply with the law while keeping customer data out of the hands of Swedish law enforcement officials. He refused to provide further details though, saying all will be revealed in due course. “I cannot reveal any details, but of course we have looked at all possible angles, including technical aspects,” he said.

He will still take the case to court, he said. “This is not the final word. How can you have a European court which decides that mass surveillance does not comply with human rights while still having a law in Sweden that is basically a carbon copy of the same criticized law?” he asked, adding that he is willing to fight the case all the way up to the CJEU again.