Iran's embassy in Moscow said in a statement there were no secret nuclear contacts between the two countries.
The embassy also said the country is transparent in its nuclear activities.
North Korea has also denied secret nuclear contacts with Iran.
Last week, North Korean state media reported that a delegation from Iran's Foreign Ministry had arrived in Pyongyang, although no further information about the visit was released.
The Proliferation Threat
The Arak heavy-water plant in central Iran (Fars)
BENDING THE RULES. Henry Sokolski, executive director of the Nonproliferation Policy Education Center, told an RFE/RL-Radio Free Asia briefing on January 9 that the West is hamstrung in dealing with Iran and North Korea because of the way it has interpreted the international nonproliferation regime to benefit friendly countries like India and Japan.
LISTENListen to the entire briefing (about 90 minutes):
Real Audio Windows Media