A conservative website with strong ties to the Republican establishment triggered the investigation into Donald Trump's past that ultimately produced a dossier alleging a compromised relationship between the president and the Kremlin.

The Washington Free Beacon website confirmed it originally retained the political research firm Fusion GPS to scour Mr Trump's background.

The website is largely funded by Republican billionaire Paul Singer.

It insisted none of the early material it collected went on to appear in the dossier compiled by former MI6 agent Christopher Steele which made claims of links between Mr Trump and Russia. These links are denied by Mr Trump.

In a statement the Free Beacon said: "During the 2016 election cycle we retained Fusion GPS to provide research on multiple candidates in the Republican presidential primary, just as we retained other firms to assist in our research into Hillary Clinton.

"The Free Beacon had no knowledge of or connection to the Steele dossier, did not pay for the dossier, and never had contact with, knowledge of, or provided payment for any work performed by Christopher Steele."

Mr Singer was backing Senator Marco Rubio in the race for the Republican presidential nomination at the time of the Free Beacon's involvement.