Washington (CNN) -- The House ethics committee on Thursday announced separate investigations into whether Rep. Laura Richardson and Rep. Maxine Waters, both Democrats from California, violated rules of conduct.
The Committee on Standards of Official Conduct issued statements saying it appointed investigating subcommittees in the cases of Richardson and Waters.
At the same time, the panel dismissed a third case involving Rep. Sam Graves, a Missouri Republican.
Richardson's case involves whether she received preferential treatment in the foreclosure and eventual re-acquisition of her home in Sacramento, California.
The committee's announcement said the investigation would focus on whether Richardson failed to make full disclosure of her holdings and if she received an "impermissible" gift or preferential treatment in her home foreclosure and its aftermath.
Waters is being investigated for allegedly seeking preferential treatment for a bank linked to her husband, the committee said. According to the panel's announcement, the investigation will look into whether Waters or her husband benefited from any of her communications or actions involving OneUnited Bank, in which her husband held stock and previously was a director.
The investigations follow recommendations by the Office of Congressional Ethics, an independent panel that includes former members of Congress and provides the committee with an outside perspective on the cases.
Graves was under scrutiny for inviting a witness with business links to his wife to testify before the House Small Business Committee. The ethic panel found no evidence of wrongdoing and dismissed the case.
CNN's Deirdre Walsh contributed to this story.