German carmaker Volkswagen and electronics giant Bosch were resisting efforts Saturday to make a huge trove of documents related to a car emissions probe in the United States available to investigators in other countries.
A court in San Francisco has been asked to provide the documents for European court proceedings related to the emissions scandal that has engulfed Volkswagen over the past year.
The company admitted installing software in about 11 million diesel vehicles aimed at manipulating emissions tests. Bosch, one of its suppliers, faces allegations that it helped to design the so-called "defeat devices."
The two firms are trying to stop some 20 million pages of documents gathered by US investigators from being used by a court in Germany which is considering over a thousand claims for compensation.
The claims were lodged mainly by private investors at the district court in the northern city of Braunschweig.
Volkswagen has long refused to provide European prosecutors with the same documents as they sent to the US, arguing that the documents were produced specially for proceedings in US jurisdiction, and were not appropriate for proceedings elsewhere.
The US court should reject the request for the documents, representatives of Volkswagen and Bosch said.