Rep. John Campbell of California said the investigation seems "semi-random," The Hill reported Wednesday.
"I can't figure it out," he said.
The Office of Congressional Ethics faces a deadline this week of whether to advance its investigation into members' votes and fundraisers just days before the House approved its Wall Street reform bill, the Washington newspaper reported. All eight lawmakers -- three Democrats and five Republicans -- have denied wrongdoing.
"There isn't a single Republican or Democrat either in this OCE thing or out of it that changed their vote," Campbell said. "Not only between the committee votes and the floor, but in the markups. All of our positions on this bill were staked out months earlier. There were no surprises. There were no changes, no turns and no surprises."
Most Democrats, including the three who are under investigation, voted for the underlying bill, while all Republicans opposed it.
Besides Campbell, the other lawmakers OCE has asked lobbyists for fundraising information on Reps. Mel Watt, D-N.C.; Joseph Crowley, D-N.Y.; Jeb Hensarling, R-Texas; Earl Pomeroy, D-N.D.; Tom Price, R-Ga.; Chris Lee, R-N.Y.; and Frank Lucas, R-Okla.
Hensarling has said the OCE has specifically requested information on fundraising events from Dec. 2-11. The House passed its financial reform bill Dec. 11.
Notable deaths of 2014 [PHOTOS]