A senior diplomat at Russia's embassy in Athens has been found dead in his apartment, Greek police say, adding that at "first sight" he appears to have died from natural causes.

Andrey Malanin, 54, was found dead on his bathroom floor by another member of embassy staff, a police official said.

According to the embassy's website, Mr Malanin was the head of the consular section.

Police have launched an investigation and the authorities were awaiting a report from the coroner, but there was apparently no evidence of a break in.

"At first sight, we are talking about natural causes," the police official said.

Police told the Associated Press that there were no signs of harm on Mr Malanin's body, but that a murder investigations unit had been called in because of his diplomatic status.

The death comes three weeks after Russia's ambassador to Turkey, Andrei Karlov, was assassinated by a riot police officer while speaking at a photo exhibit in Ankara.