(ANSA-AFP) - BELGRADE, APR 8 - Slovakia's drug regulator said Thursday it was not able to determine the safety of a batch of Russia's Sputnik V vaccine delivered to Bratislava last month, voicing misgivings about its composition. The EU member state of 5.4 million people is battling one of the highest Covid-19 death rates in the world. Former prime minister Igor Matovic was forced to step down last week amid a scandal over his hasty purchase of two million doses of the Sputnik V vaccine, which so far has not received a green light from the European Medicines Agency (EMA) for use in the European Union. "Batches of (Sputnik V) vaccine used in preclinical tests and clinical studies published in the Lancet journal do not have the same characteristics and properties as batches of vaccine imported to Slovakia," the State Institute for Drug Control (SUKL) said a statement. (ANSA-AFP).