Mr Nebenzya said: “It’s some sort of theatre of the absurd.
“Couldn’t you come up with a better fake story?
“We have told our British colleagues that ‘you are playing with fire and you will be sorry’.”
In his speech to the UN, Mr Nebenzya also claimed there was ”a propaganda war” against Russia going on, seeking “to discredit and even de-legitimise Russia”.
His blistering words follow the revelation that the deadly substance used to poison the Skripals was produced at the Shikhany military research base in south-west Russia, according to The Times.
As the amount of nerve agent detected by the British intelligence was not enough to be used in a warzone, it was suggested it may have been stockpiled to be used in targeted attacks, The Times reported.
The UN meeting was called by Russia on the same day it saw its suggestion to carry out a joint investigation into the poisoning voted down by the international Organisation for the Prohibition of Chemical Weapons (OPCW) at The Hague.
British Ambassador to the UN Karen Pierce told the Security Council that the UK’s action “stand up to any scrutiny” and promised he will keep the UK up to date on the inquiry.
He added: “We have nothing to hide … but I do fear that Russia might have something to fear”.
Deputy US Ambassador Kelley Currie said Washington firmly believed “that Russia is responsible for this chemical weapons attack on UK soil”.
In the aftermath of the poisoning, which took place on March 4, Prime Minister Theresa May said it was “highly likely” that Russia was behind the attack.
The UK and its Western allies have so far expelled more than 150 diplomats, triggering the retaliation of Moscow which, in turn, expelled diplomats from the UK, the US and other European countries.
Meanwhile, on Thursday, Yulia Skripal released her first statement since the attack, confirming that she was recovering in hospital and her “strength is growing daily”.