James Dornan told viewers during his appearance that a poll published on Tuesday morning had shown that 54 per cent of Scots wanted to leave the UK.
He made the claim after his interviewer on RT said support for Scottish independence was still at roughly the same level as it was in 2014, when 45 per cent of people voted Yes.
“As a matter of fact there was a poll this morning that showed independence support was up to 52 per cent I think...54 per cent. Against it was 46. So I think we’re in a good place just now,” he said.
Mr Dornan later admitted that he had made a “mistake”, posting a link to his Twitter followers showing that the Survation poll was two years old and conducted a few days after the Brexit vote.
He said he had wrongly thought it was new research as it had “popped up” on his Twitter feed on the day he gave the interview.
It is the second time this week that an SNP politician has caused controversy through an appearance on RT, which has been criticised by some of the party’s MPs and MSPs, including Nicola Sturgeon.
On Monday, the broadcasting regulator Ofcom ruled that Alex Salmond’s chat show on the channel had broken its rules within minutes of the first programme going on air.
It said the first edition of The Alex Salmond Show, broadcast last November, had misled its audience by presenting a series of messages as if they were from viewers.
Its investigation established that most of the messages were actually from production staff, including a freelance cameraman and a make up artist.
Scottish Conservative leader Ruth Davidson claimed Mr Dornan had been “caught telling fibs on Russian state propaganda”, describing he and Mr Salmond as “Putin’s useful idiots”.
“It seems @AlexSalmond isn’t the only SNP figure caught telling porkie pies on Putin’s propaganda arm. [James Dornan] has been at it as well,” she wrote on Twitter.
Mr Dornan then hit back, claiming that the Tories were trying to deflect attention away from their “dark money, Brexit fiasco, manipulating of democracy scandals”.
He was referring to claims that a trust with links to the Scottish Tories may have been used to obscure the source of funds given to the party, which has been dubbed “Dark Money”.
“I made an error and then put my hands up, you should try it sometime, feels good,” he told Ms Davidson. “Talking of useful idiots, has Theresa [May] given you permission to talk about Dark Money yet?”
An SNP spokeswoman said: “James Dornan made a mistake, by citing an out of date poll – unlike Ruth Davidson, who has been officially rated as Scotland’s most untrustworthy political leader, who wilfully misled people about the consequences of a No vote in 2014 and for the last two years has sought to defend the indefensible shambles of Brexit.
“She is clearly rattled by the fact that support for independence remains at historically high levels, with almost 90 per cent of polls since the referendum showing support above 2014 levels.
“And last month’s Scottish Social Attitudes survey showed that the numbers who view independence as positive for Scotland’s economy now outnumber those who believe otherwise.”