The former British spy behind a controversial dossier about Donald Trump’s Russian links has spent two days talking to US investigators, it was reported on Wednesday.

Christopher Steele met behind closed doors with colleagues of Robert Mueller, the special counsel looking into Russian election meddling, according to The Washington Post.

It means that investigators will be able to judge firsthand whether they think claims reported by Mr Steele in the dossier are trustworthy.

Mr Steele has previously refused requests to appear before Congressional committees looking into how Russia interfered in the 2016 election.

The Washington Post also reported that Mr Steele compared possessing the information he found about Mr Trump to “sitting on a nuclear weapon”.

The paper's 4,000-word article provides the fullest picture yet of how Mr Steele acted after uncovering claims that the Russians had compromising material on Mr Trump.