Former first minister Alex Salmond has insisted he holds no brief from the Kremlin on his RT show, branding the Salisbury nerve agent attack a "heinous crime".
Mr Salmond has faced calls to end his relationship with RT but said it has not been a "propaganda station" because it is regulated under a UK licence by Ofcom.
He discussed the Salisbury attack on The Alex Salmond Show on Thursday morning, interviewing guests including a former MI5 officer and commentator Mary Dejevsky and human rights activist Peter Tatchell.
Mr Salmond said that his show is independently produced, and added: "I hold no brief from the Kremlin, nor am I required to have. No-one has tried to influence the contents of this show in any way, shape or form whatsoever."
Commenting on the incident, he said: "The chemical poisoning in Salisbury was a heinous crime and should be universally condemned."
Mrs May announced sanctions in the House of Commons on Wednesday in the wake of the attack on ex-spy Sergei Skripal and his daughter Yulia, including the expulsion of 23 Russian diplomats.
Mr Salmond said that while the UK Government is totally convinced that the Russian state is involved and is therefore entitled to take a range of additional measures, diplomatic and economic, it is "much more effective" to operate with friends and allies.
On Wednesday, Labour leader Jeremy Corbyn was barracked by Conservative MPs as he asked the Prime Minister how she had responded to requests from the Russian government for a sample of the nerve agent used in the attack so it could run its own tests.
Mr Salmond said: "To succeed, the evidence has to be overwhelming and the case cast iron - as the leader of the Opposition correctly pointed out to the PM. He didn't get much support for making that point in the House of Commons but that doesn't make him wrong.
"Pursuing the case internationally is essential and you're unlikely to succeed at the Organisation for the Prohibition of Chemical Weapons or at the United Nations without the production of such conclusive evidence.
"When the UK Government produces their evidence then the Russian government will have no alternative but to answer."
Former Liberal Democrat leader Sir Menzies Campbell called for Mr Salmond to consider if he should continue to broadcast on the Russian state-owned TV channel.
Speaking on BBC Radio Scotland's Good Morning Scotland programme, he said: "I think Mr Salmond really ought to reconsider his position.
"The fact that he is associated with a broadcasting outlet which is very largely believed to be under the control of the Russian government at this particular moment may be thought by many people, to put it mildly, to be unfortunate."
Ofcom has said it will consider the implications for RT's broadcast licences in the wake of Mrs May's statement in the House of Commons.
Mr Salmond said that censuring broadcasters would make a "mockery of freedom of speech".
He said: "Don't shut down TV stations because your standpoint is so uncertain that you must exclude other perspectives.
"Between Monday and yesterday the PM sensibly drew back from that proposal but nor should this be attempted by indirect pressure on an independent regulator."
He rounded off the programme with the words "until next week, I hope".