The man is being named inlocal media sources as Sean Quinn (52), a finance executive working for a construction company involved in development near St Petersburg airport.
The man’s body was discovered outside an apartment block in the Primorskey area of St Petersburg at 1am yesterday.
Police are said to be investigating what Mr Quinn was doing in the area, as he was staying in a city centre hotel an hour’s drive away from the location.
The deceased was in Russia on a working visa.
According to reports, there was no CCTV in the residential area where he died.
His body was sent for a post mortem while an investigation was launched into what happened.
A police spokesman told a local radio station: “We are checking.”
The Irish Sun reports there is no suggestion of foul play, although there have been a number of cases of individuals dying in building plunges in Russia in recent years.
Last August, Bruno Charles De Cooman, a Belgian working for Russian Group Novolipetsk Steel, was found dead outside his home in Moscow.
His mother has since claimed he was murdered, saying he asked his Belgian driver to wait for him outside while he went up to his ninth floor apartment.
The previous April, Russian investigative journalist Maksim Borodin fell from a fifth floor window in Ekaterinburg.
The Department of Foreign Affairs has said it is aware of the case and providing consular assistance.