The American Family Voices' complaint accuses Issa of using his position as chairman of the House Oversight and Government Reform Committee to enhance his fortune, The Hill reported Tuesday.
The complaint, to be filed with House Office of Congressional Ethics, was obtained by The Hill.
"We're filing an ethics complaint against Rep. Darrell Issa this morning. Issa has repeatedly used his public position for personal gain, and should be held accountable," the non-profit advocacy group for middle- and low-income families on economic, healthcare and consumer issues posted Tuesday on its Facebook page.
A spokesman for Issa said Monday the allegations had no merit and were part of a White House-sponsored attack.
"This complaint is entirely without merit. The White House has used an assortment of outside progressive groups in an effort to attack [the committee] and Chairman Issa directly. This is just their latest salvo in an ongoing effort to obstruct oversight," said Frederick Hill, Issa's spokesman.
Among other things, the complaint alleges Issa pressured the Securities and Exchange Commission to stop an investigation of Goldman Sachs soon after he bought a stake in a Goldman high-yield mutual fund. The document also claims Issa used his authority to improperly defend Merrill Lynch, a firm with "which he has a significant financial interest."
"In fact and in appearance, Rep. Issa has repeatedly -- and impermissibly -- used his public position to promote his private financial interests," American Family Voices President Mike Lux wrote in a letter to former Reps. Porter Goss, R-Fla., and David Skaggs, D-Colo., OCE co-chairmen.