WASHINGTON — U.S. Rep. Joaquin Castro, D-San Antonio, fired a computer contractor last month after learning that he and his family were being investigated by U.S. Capitol Police, Castro said Thursday.

A spokeswoman for Castro said the employment of Jamal Awan, who worked as a computer systems contractor for Castro and more than two dozen other House Democrats, was terminated on Feb. 2.

Awan and three family members are being investigated for alleged theft and other computer-related issues, according to the Daily Caller News Foundation, a conservative news and opinion website. Politico reported that a fifth person is under investigation.

A U.S. Capitol Police spokeswoman declined Thursday to provide an update, saying her agency does not comment on ongoing investigations.

Castro is among at least 30 Democratic House members who employed the contractors on a shared basis, according to a San Antonio Express-News review of House expenditures for the fourth quarter of 2016, the most recent available.

Members share the cost of the contractors. For instance, Castro’s portion of Awan’s payment for the quarter was $3,250, records showed. According to published reports, the staff members received as much as $160,000 yearly from the various congressional offices.

In a statement, Castro said: “I instructed my office to terminate this individual’s contract immediately when I learned he violated his conditions of employment.”

Castro is one of three House Intelligence Committee members who contracted with the IT specialists. Castro added in his statement that “no sensitive information is shared electronically with members of the committee or their offices.”

Jack Langer, a spokesman for Rep. Devin Nunes, R-Calif., chairman of the Intelligence Committee, said the committee maintains a separate IT staff.

Referring to the investigation, Langer said in an email that “these staffers worked for the personal offices of various Democratic members of Congress, and the staffers would not have had access to House Intelligence Committee classified information.”

House aides described a common practice of seeking referrals from other members about computer work. Castro contracted with Awan in July 2014 during his first term in Congress. The contractor did not work out of Castro’s office but was available for troubleshooting and computer tasks.

Congressional contractors are chosen from lists provided by the House Administration Committee after prospective contractors are vetted. A spokeswoman for the GOP-run committee did not respond to phone and email requests about the people under investigation.

bill.lambrecht@hearstdc.com