Three journalists from CNN resigned after writing a report about a secret meeting between a man close to US President Donald Trump and a Russian investment fund manager turned out to be false.

CNN has retracted the report.

Anthony Scaramucci, the Trump adviser who is the target of the story, told Fox News reporter Howard Kurtz that he has no plans to sue the network and wants to move on.

However, added: “I was disappointed the story was published. It was a lie.”

President Trump slammed CNN for the report on his Twitter account Tuesday. "So they caught Fake News CNN cold, but what about NBC, CBS & ABC? What about the failing @nytimes & @washingtonpost? They are all Fake News!"

CNN's troubles continued when investigative organization Project Veritas published a video online in which senior CNN producer John Bonifield appeared to admit that the continuing allegations of collusion between Trump and Russia during the 2016 US Presidential election lacks evidence.

The conversation was filmed with a hidden camera.

“I haven’t seen any good enough evidence to show that the President committed a crime," Bonifield said.

He admitted that the staff has a bias against the president. “I know a lot of people don’t like him and they’d like to see him get kicked out of office…”

“I think the President is probably right to say, like, look you are witch hunting me...you have no real proof," he added.