Congressional investigators want to interview President Trump’s longtime bodyguard who personally delivered the letter firing former FBI Director James Comey to the agency as part their probe into Russian interference in the 2016 election, according to a report on Thursday.

Keith Schiller, a former NYPD cop who has been at Trump’s side for 20 years and who now serves as the White House director of Oval Office operations, is on the witness list for the House Intelligence Committee, ABC News reported.

Schiller is among a number of Trump associates the House panel wants to interview — including former National Security Adviser Michael Flynn, Trump’s son-in-law and top White House adviser Jared Kushner, former Trump campaign manger Paul Manafort and former campaign associate Roger Stone.

The four have denied any wrongdoing and agreed to cooperate in the probe.

The House Intelligence Committee’s probe is among a number of investigations ongoing into Russian meddling in the election and any links to the Trump campaign.