A Russian man working for a nuclear company in Iran has been found dead after disappearing 18 days earlier, Iranian media and a Russian spokeswoman said Thursday.

According to the state-owned Iran newspaper, the man's frozen body was found Tuesday at a recreational area in a mountainous area just outside of Tehran, where nighttime temperatures dip well below freezing.

Iran is building its first nuclear power plant with Russian help in the southern port of Bushehr, which is expected to go on line next year. Russia has backed limited U.N. sanctions aimed at forcing Iran to suspend its uranium enrichment program, but has staunchly opposed the U.S. push for harsher measures.

Meanwhile, a spokeswoman for the state-run Russian company coordinating the Bushehr project, Atomstroiexport, said the deceased was an employee and that he died in an accidental fall from a rock in the recreational area.

The spokeswoman, Irina Yesipova, would not identify the man or give specifics about his job. She said the area is a popular weekend getaway destination

The Iranian newspaper said the Russian was a legal expert and that his death is being investigated. Also, the semiofficial ILNA news agency said the 57-year-old man was on a short assignment to Iran and disappeared Nov. 22.

The Iranian reports also did not identify the man.