German law enforcement authorities have confirmed a take-down of Pirate Party servers on Friday.
The Bundeskriminalamt (BKA) German federal police told ZDNet UK on Monday that it was involved in the investigation.
The operation saw German Pirate Party (Piraten Partei) servers taken offline, disrupting operations.
Prosecutors in Darmstadt led the German side of the operation, said a BKA spokeswoman.
Darmstadt attorney Tobias Stewen told ZDNet UK on Monday that the investigation had been initiated at the behest of prosecutors in Paris.
"French investigative measures in Germany were considered necessary," said Stewen. "The Paris prosecutor asked the German authorities to execute investigative measures."
Stewen declined to comment further.
The Piraten Partei speculated on Friday that German police were interested in looking at logs for PiratePad collaborative software, which may have been used by people unconnected with the party to plan a criminal act.
The servers were not confiscated, but remained on the premises, disconnected from the internet, a Pirate Party spokesman told ZDNet UK on Friday.