WASHINGTON • The presidential campaign of Mrs Hillary Clinton and the Democratic National Committee (DNC) paid for research that was included in a dossier made public in January that contained salacious claims about links between President Donald Trump, his associates and Russia.
A spokesman for a law firm said it had hired Washington-based researchers last year to gather damaging information about Mr Trump on numerous subjects - including possible ties to Russia - on behalf of the Clinton campaign and the DNC.
The revelation, which emerged from a letter filed in court on Tuesday, is likely to fuel new partisan attacks over federal and congressional investigations into Russia's attempts to disrupt last year's election and whether any of Mr Trump's associates assisted in the effort.
The President and his allies have argued for months that the investigations are politically motivated. They have challenged the information contained in the dossier, which was compiled by a former British spy who had been contracted by Washington research firm Fusion GPS.
Fusion GPS began working for the law firm, Perkins Coie, in April last year, according to the letter written by Perkins Coie managing partner Matthew Gehringer. It added that Fusion GPS had already been conducting the research "for one or more other clients during the Republican primary contest".
Perkins Coie was paid US$12.4 million (S$16.9 million) to represent the Clinton campaign and DNC during last year's campaign, according to the filings.
Fusion GPS had hired Mr Christopher Steele, a respected former British spy with extensive experience in Russia, to conduct research into any possible links between Mr Trump, his businesses, campaign team and Russia. Mr Steele produced memos that alleged a broad conspiracy between the Trump campaign and the Russian government to influence last year's election.
A spokesman for the DNC has sought to distance the national party from the work, noting that party chairman Tom Perez was elected only after last year's election.