The health of Dmitry Kovtun, a witness in the case of the poisoning death of former spy Alexander Litvinenko,continued to deteriorate, the Interfax news agency reported on Friday.

"Kovtun has an acute form of radiation sickness, with internal contamination from alpha-radiation by radio-nuclides affecting the liver, the kidneys, and the intestines," Interfax quoted a source as saying.

Kovtun is conscious after emerging from a coma. He was interrogated on Tuesday and Wednesday and fell into a coma on Thursday.

Kovtun is the business partner of Andrei Lugovoi, whom Britain views as a key suspect in the Litvinenko probe and is also undergoing medical tests at a hospital in Moscow.

Kovtun is also under Scotland Yard's attention, because he met with Litvinenko in London in October.

Litvinenko died of radioactive poisoning in London on Nov. 23. Experts investigating his death have found radiation traces at a dozen locations and on two British Airways planes that flew the Moscow-London route.

Source: Xinhua