A data breach of 1.7 TB has revealed the details of Russian surveillance on the network of the Russian telecom provider MTS, reports the US internet security company UpGuard on Wednesday in collaboration with the news site TechCrunch .

This includes almost 200,000 documents, an archive of 245 GB of e-mails and 578,000 photos. One part of the leaked data deals with the SORM system, with which the secret services in Russia can tap the telecom traffic for analysis.

According to UpGuard, the documents mainly deal with the installation of SORM hardware between 2014 and 2016. The Finnish telecom manufacturer Nokia collaborated with MTS for this. The database would have been leaked because a Nokia employee had not secured it properly.

In a statement to TechCrunch , Nokia says it has launched an investigation. The database in question is no longer connected to the internet, according to a spokesperson.

Social media and telecom companies in Russia are legally obliged to cooperate in the installation of SORM equipment. This is extra controversial in Russia, because human rights are under pressure in the country.