A freshman member of the conservative House Freedom Caucus is calling for special counsel Robert Mueller to recuse himself from the Russia investigation because he has brought on "highly partisan" lawyers to help with the probe.

"Special Counsel Robert Mueller should recuse himself because the integrity of his appointment is in question due to former FBI Director James Comey's manipulative leaks and the relationship between Mr. Comey and Mr. Mueller," Rep. Andy Biggs, R-Ariz., said in a statement Friday. "His ability to be impartial is doubtful because he has surrounded himself with highly partisan lawyers who make a special practice to line the coffers of Democrats."

News outlets have reported at least three lawyers Mueller has hired to help conduct his investigation have donated almost exclusively to Democrats. Also, Mueller and Comey are friends and former colleagues.

Biggs is at least the second House Republican to call for Mueller's recusal.

Earlier this month, Rep. Louie Gohmert, R-Texas, told the Blaze that Mueller should step aside from the probe because of his "cozy relationship" with Comey.

As part of his investigation into Russia's election interference, Mueller will probe for possible collusion between the Trump campaign and Russia. The Washington Post reported Mueller will also investigate whether Trump obstructed justice by allegedly telling Comey that he hoped the bureau would end its probe of Michael Flynn, Trump's first national security adviser. Another report Sunday said Mueller hasn't decided yet whether to investigate Trump.

Most Democrats and Republicans in Congress have defended Mueller, the former FBI director whose leadership of the bureau lasted longer than anyone after J. Edgar Hoover.