The first interview with the prime suspects in the Salisbury nerve agent attack is expected to be broadcast by Russian state-funded news channel RT.
The global news channel, funded by the Russian Federation, tweeted that the discussion with Alexander Petrov and Ruslan Boshirov would be aired “soon”.
Editor-in-chief Margarita Simonyan said the pair had called her mobile and the interview, which is in Russian, will be published later on Thursday.
On Wednesday the British Government said it stood by its assertion that the two men were officers in Russian military intelligence service the GRU, after President Vladimir Putin described them as “civilians”.
UK authorities believe the pair smeared the highly toxic chemical Novichok on a door handle at the Wiltshire home of former GRU officer Sergei Skripal, leaving Mr Skripal and his daughter Yulia critically ill.
Mr Putin said the men had been discounted as members of his security network.
In an address to the Easter Economic Forum in Vladivostok, he said: “Of course, we looked who these people are. We know who they are, we have found them already.”
Questioned on whether the pair were civilians, he replied: “Of course they are civilians.”
The Russian president said he hoped Mr Petrov and Mr Boshirov would appear in public to dispel doubt about their true identity.
Detectives believe it is likely the two suspects, thought to be aged around 40, travelled under aliases and that Petrov and Boshirov are not their real names.
Officers formally linked the attack on the Skripals to events in nearby Amesbury where Dawn Sturgess, 44, and her partner Charlie Rowley, 45, were exposed to the same nerve agent.
Ms Sturgess died in hospital in July, just over a week after the pair fell ill.
A police officer who visited the home of the Skripals shortly after the attack, Nick Bailey, was also left critically ill from exposure to the substance.