A new claim by two writers who work for liberal leaning news outlets is sure to turn heads Thursday.

President Barack Obama’s 2012 campaign hired controversial research group Fusion GPS to dig up dirt on then-Republican presidential nominee Mitt Romney, a new book claims — raising questions about Democrats’ possible long-standing ties to the group.

Fusion GPS is the opposition research firm behind the much-discredited Trump dossier, which contained “salacious” and “unverified” allegations about then-candidate Donald Trump. The dossier cited Russian sources who said Russia had information that compromised Trump.

The firm was retained by Marc Elias, an attorney representing both the Hillary Clinton 2016 campaign and the Democratic National Committee. But “Russian Roulette: The Inside Story of Putin’s War on America and Donald Trump’s Election,” written by Yahoo’s Michael Isikoff and Mother Jones’ David Corn and published Tuesday, reports that the relationship between Democrats and Fusion goes back a lot further, to at least 2012.

“In 2012, Fusion GPS was hired to do opposition research on Mitt Romney for Barack Obama’s re-election campaign,” the book claims. According to the book, the 2012 Obama campaign’s payments to the group were never publicly disclosed.