European investigators raided the offices of Northern Data, a data center operator in the midst of pivoting from cryptomining to AI hosting.

Germany’s Federal Criminal Police carried out raids on Northern Data’s Frankfurt offices, while the Swedish Economic Crime Authority and the tax authority’s crime investigators raided its operations in Boden, Sweden.

Authorities are investigating whether Northern Data mined Bitcoin at its Boden data center. The country increased taxes on mining in 2023.

“Northern Data has been actively engaged with a European tax authority and are surprised by the escalation over recent days,” said a Northern Data spokesperson.

“Northern Data believes there is a misunderstanding of tax treatment of its GPU offering, which is solely dedicated for cloud computing, and the economic and legal structure of the company’s legacy crypto mining operations.”

Northern Data said that it believes it is in compliance with international tax standards and is working to resolve the situation.

“Four people have been arrested in connection with an investigation into large-scale VAT fraud,” a spokesperson for the Swedish Economic Crime Authority told Bloomberg, adding that the tax evasion is estimated to be more than €100 million.

Swedish tax authorities are investigating a number of cryptominers for possible tax fraud.

Northern announced plans to sell off its crypto business this August to Elektron Energy. The $235 million sale of the ‘Peak Mining’ division is expected to close later this year.

Northern Data is majority-owned by cryptomining company Tether, which also owns a stake in rightwing video site Rumble.

Last month, Rumble announced that it was in talks to acquire Northern Data.

Northern Data’s Taiga Cloud unit operates more than 22,000 GPUs. Ardent Data Centers has approximately 250MW of power deployed or coming online across eight global data centers by 2027, according to Northern.

Ardent operates data centers in Boden, Sweden; Lefdal and Kristiansand, Norway. The Lefdal site is hosted by Lefdal Mine, and Kristiansand by Bulk. In June 2025, Northern launched a Pittsburgh, Pennsylvania, data center that will be operated by Ardent.

The company is also planning a large development in Maysville, Georgia. Northern’s most recent earnings presentation says the group also has colocation capacity in the UK and Portugal. Its website also lists a 6MW site in Amsterdam, the Netherlands.

In May of this year, Northern Data said that it had received expressions of interest from unnamed “US-listed companies” to enter into discussions focused on merging or acquiring its Taiga Cloud and Ardent divisions.