WATCH: Radiation leak from sunken Russian nuclear sub 'no threat' - Norway researchers
The Komsomolets was a Russian nuclear-powered attack submarine that was built in the 1980s.
The submarine sank in the Norwegian Sea 30 years ago and is leaking high levels of radiation. Scientists, however, say that there is no danger to humans or marine life.
The level of radioactive caesium found in one sample was 800 000 times higher than normal, while other samples found lower levels of radiation.