MOSCOW (Sputnik) — Russia regrets that the case overshadows relations between Moscow and London, Foreign Ministry spokeswoman Maria Zakharova said.
"There was no reason to expect that the final report of а politically engaged and highly non-transparent process, with a predetermined result, could be objective and impartial," Zakharova said in a written comment on the report issued earlier in the day.
She added that Russia's position on this issue remained unchanged and well-known.
"We regret that a purely criminal case was politicized and marred the general atmosphere of our bilateral relations," she pointed out.
Following his death, UK authorities claimed that Litvinenko's former colleagues had poisoned him with the radioactive isotope polonium-210. A public inquiry into Litvinenko's death was formally established by the UK government in July 2014.
"We need time to study in detail the content of this document [UK report on Litvinenko's case], and then we will give a detailed assessment," Zakharova added.