Russia's state nuclear corporation Rosatom on Monday denied a reported virus contamination in the Iranian Bushehr nuclear power plant (NPP)'s computer system.

Earlier in the day, British newspaper Daily Telegraph said a Stuxnet virus, which was developed at Israeli Dimona NPP, had installed itself into the computers of the NPP built by Russians, also Iran's first one.

However, according to Sergei Novikov, a Rosatom spokesman, "there are no viruses in the power plant's computer network, especially in units responsible for security, because this network is totally autonomous and isolated from external sources."

The Daily Telegraph referred to some Russian specialists working in Bushehr, saying that the virus had already done "enormous damage" to the reactor and that Russian team "cannot guarantee safe activation of the reactor."

"Russian nuclear officials have warned of another Chernobyl-style nuclear disaster at Iran's controversial Bushehr reactor because of the damage caused by the Stuxnet virus," the newspaper said.

In response, Rosatom said the virus had not sneaked into the automatic control system of the NPP's technological processes, and stressed that nothing has endangered the reactor control system.

Fears about possible aftermath of the Stuxnet computer virus on Bushehr NPP's security first appeared in October 2010, when Russian technicians started loading the first nuclear rods into the reactor.

The commercial launch of the Bushehr NPP was expected within weeks, according to Russia's Foreign Ministry.