WASHINGTON — The House Ethics Committee said Wednesday it will open an investigation into Rep. Henry Cuellar, a Texas Democrat who was recently indicted in a federal bribery case.

The panel said in a statement that it had unanimously voted to form a subcommittee tasked with investigating Cuellar after the Justice Department this month released an indictment accusing Cuellar and his wife, Imelda, of accepting $598,000 in bribes from foreign entities, including a Mexican bank and an oil and gas company controlled by Azerbaijan.

The subcommittee will have jurisdiction to investigate whether Cuellar “solicited or accepted bribes, gratuities, or improper gifts; acted as a foreign agent; violated federal money laundering laws; misused his official position for private gain; and/or made false statements or omissions on public disclosure statements filed with the House.”

Before the charges were unsealed earlier this month, Cuellar denied any wrongdoing and said he had “proactively sought legal advice” from the panel.

In a statement Wednesday, Cuellar reaffirmed his innocence.

“I respect the work of the House Ethics Committee,” Cuellar said. “As I said on May 3rd, I am innocent of these allegations, and everything I have done in Congress has been to serve the people of South Texas.”

The House Ethics Committee in Wednesday’s statement cited House rules that require the panel to establish an investigative subcommittee or explain their decision not to within 30 days of a member being indicted or otherwise charged.

Chairman Michael Guest, R-Miss., and Rep. Glenn Ivey, D-Md., will serve as the chair and ranking member of the new subcommittee.

The federal indictment is poised to make Cuellar’s seat more vulnerable in November. Two years ago he easily defeated his Republican opponent, Cassy Garcia.

This time around, Cuellar is set to face retired Navy officer Jay Furman, who won a Republican primary runoff election on Tuesday.

Cuellar and his wife are not the first congressional couple to face charges in a foreign bribery scheme in the past year. The Justice Department hit Sen. Bob Menendez, D-N.J., and his wife Nadine Menendez with 18 criminal charges tied to bribery and corruption. They have pleaded not guilty. The New Jersey senator is currently on trial.

Rebecca Kaplan reported from Washington, D.C., Zoë Richards reported from New York.