Britain has exterminated evidence in the Salisbury spy poisoning and has benefited politically from the incident, Russia's foreign minister has claimed.
Sergey Lavrov also said the Government had "grossly manipulated" the chemical weapons watchdog when it orchestrated a change in the rules to allow it to identify who is responsible for attacks.
The minister described the poisoning of former Russian spy Sergei Skripal and his daughter Yulia as a "very bad crime" but said the "inconsistencies" in the case were "very troubling".
He told Channel 4 News: "Boris Johnson recently mentioned that the place is being disinfected... six months or four months after the incident... and the policeman became miraculously fine... the Skripals became miraculously fine... people now talk about levelling the house where they lived... levelling the house of the policeman.
"It all looks like consistent physical extermination of the evidence.
"Like the benches in the park were removed immediately and of course the video images when the policeman or special forces in special attire go to take a look at this bench, there's people without any protection moving around.
"It all looks very weird, you know."
Asked if he was accusing the British state of a cover-up, he replied: "I don't exclude this, as long as they don't give us information."
"Certainly, the UK has benefited politically from what is going on and it's an interesting situation whereby a country that is leaving the EU is determining the EU policy on Russia," he added.
Mr Johnson led a successful bid at the Organisation for the Prohibition of Chemical Weapons (OPCW) to reform its remit in the wake of the Salisbury poisoning and repeated attacks in Syria.
Russia opposed the move and Mr Lavrov suggested it would pull out of the watchdog if the decision is not reversed, saying it would not be a "universal organisation".
He claimed "all kind of tricks" were used to secure a majority in the vote on the changes at the OPCW, including "mobilising small countries that don't have any representation in The Hague, paying for their travel expenses, paying for the hotel bills".