Argentine parliamentarians are reportedly investigating two German firms over the replacement of batteries on the missing submarine ARA San Juan, alleging bribes were paid to secure contracts and inferior products used.

The German Interior Ministry has received a request for information from the Foreign Affairs Commission of the Argentine parliament, officials confirmed to public broadcaster Bayerische Rundfunk (BR).

“The suspicion exists that the batteries that were replaced were not, in part or at all, of the quality that they should have been. We don’t know either where they came from, whether from Germany or from another country. Because of this we want to know what technicians were there and who signed saying: good, this is repaired,” Cornelia Schmidt-Liermann, head of the Argentine parliamentary commission, said according to the network.