Senate Judiciary Committee Chair Chuck Grassley (R-IA) asked for correspondence between Christopher Steele, the author of the Trump dossier, and a former associate deputy attorney general, according to a Monday Politico report.

Grassley reportedly sent a letter to Deputy Attorney General Rod Rosenstein asking for all written and electronic communication between Christopher Steele and Bruce Ohr, a fringe figure in the Russia probe targeted by conservatives on the Hill.

Grassley reportedly wants the records to ensure that Ohr did not continue to feed the FBI information from Steele after the intelligence agency grew concerned about Steele’s communication with news outlets and distanced itself. Per Politico, Grassley also asked for a transcribed interview with Ohr.

As part of his efforts scrutinizing the FBI’s conduct during the 2016 election, Grassley has long raised concerns about Ohr, whose wife worked for the firm that funded Steele’s dossier.