The European Union’s drug regulator will begin its investigation next week into the clinical trials in Russia of the Sputnik V vaccine and whether those tests — to ensure efficacy and safety — followed “good clinical practice,” the Financial Times reports.

The U.K.-based newspaper cited anonymous sources familiar with the European Medicines Agency (EMA)’s approval process as expressing ethical concerns over the testing of Sputnik V in preparation for its use in the fight against COVID-19 in Russia and around the world.

It quoted Kirill Dimitriyev, the head of the Kremlin’s sovereign wealth fund, which backed Sputnik V’s development, as saying “there was no pressure [on participants in testing] and Sputnik V complied with all clinical practices.”

EMA approval will hinge in part on determining whether the Russian clinical trials met so-called GCP standards, the newspaper reported.

Russian President Vladimir Putin mounted an all-out race for a vaccine ahead of domestic registration of the Sputnik V vaccine in August before a third stage of clinical tests on large segments of volunteers could be completed.

It is being widely used in Russia and dozens of other countries despite early misgivings about data secrecy and reliability among medical experts.

A study published in February in The Lancet, a prestigious peer-review publication in the United Kingdom, eased some international concerns by saying Sputnik V “appears safe and effective.”

But it has received neither U.S. nor EU regulatory approval, although EU members Hungary and Slovakia have purchased it, even as the scramble for vaccinations to beat COVID-19 around the world intensifies.