The Senate Intelligence Committee said Thursday that it would not investigate whether President Donald Trump obstructed justice by interfering in the FBI probe of his associates’ possible collusion and coordination with Russia during the 2016 campaign.

“It’s never been part of our” investigation, committee Chair Richard Burr (R-NC) told CNN on Thursday, referring to obstruction of justice. Burr noted that “[o]bstruction is criminal — there’s a criminal aspect to that.” Ranking Member Mark Warner (D-VA) told the network: “The criminal piece of the investigation will be handled by the special counsel, but if we find facts we can turn this over to the special counsel.”

CNN noted that Burr and Warner had earlier met with special counsel Robert Mueller, who is reportedly investigating whether Trump obstructed an investigation.

The Senate Judiciary Committee chair, meanwhile, indicated Thursday morning in a letter to the committee’s ranking member that the committee would look into “improper partisan interference in law enforcement investigations.”

Judiciary Committee Chair Chuck Grassley (R-IA) had acknowledged Tuesday that the committee’s ranking member, Sen. Dianne Feinstein (D-CA), asked that the committee look into potential obstruction of justice in a letter to him on Friday.