MOSCOW (UPI) -- A Russian businessman who died recently of mysterious causes was apparently killed by his chair, which was found after his death to be highly radioactive, Russian newspapers reported Friday.

Investigators discovered that the deadly office chair was the source of 1.5 million times more radioactivity than normal background levels, causing fatal radiation poisoning in the man, the daily Moscovsky Komsomolets said.

The man, indentified only as V. Kaplun, was general manager of a Moscow-based private firm and had been hospitalized for over a month before his death last week. Doctors had been unable to diagnose his ailment, though one physician said the symtoms resembled those of radiation poisoning.

The dead man's colleages at the firm discovered the chair's potency after they decided to inspect the office with a Geiger counter and found levels off the scale.

Civil defense inspectors found radiation levels on two floors of the building of 120 to 200 roentgen per hour, the trade union daily Trud reported.

Inside the man's office, the paper said, "radiation levels were enormous, comparable to only Chernobyl." The building was immediately cordoned off.

Other employees of the firm will be examined for signs of radiation poisoning. It was not known how the chair became radioactive, though there have been other incidents in Moscow where ordinary household items and even foods have been found to be radioactive.