WASHINGTON — A House investigative committee issued subpoenas late Wednesday afternoon to the State Department, seeking a deeper look into former secretary of state Hillary Rodham Clinton’s nearly exclusive use of personal emails to do her official business during her tenure, the committee confirmed Wednesday.

The House Select Committee on Benghazi, which first discovered Clinton’s use of a personal email based on a home server in its inquiry into a fatal 2012 terrorist attack on a U.S. diplomatic compound in Benghazi, Libya, is asking for all emails related to the attack from all Clintonemail.com accounts and any other staff members’ personal accounts.

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Hillary Rodham Clinton has yet to comment publicly on her use of private email while serving as secretary of state.

“The Select Committee on Benghazi today issued subpoenas for all communications of former Secretary of State Hillary Clinton related to Libya and to the State Department for other individuals who have information pertinent to the investigation,” according to a statement by committee spokesman Jamal Ware. “The Committee also has issued preservation letters to internet firms informing them of their legal obligation to protect all relevant documents.”

The move escalates the panel’s conflict with Clinton and could complicate her expected run for president.

Numerous federal records and legal experts have questioned Clinton’s use of a personal email for government business and whether it violated the Federal Records Act. Her practice was first reported by The New York Times on Monday.

Committee staff learned of the Clintonemail.com domain name in reviewing records they obtained this summer, according to one person familiar with deliberations. Staffers later discovered evidence suggesting that “at least a small group of Clinton staffers” was using personal emails to conduct government work and correspond with the secretary, the person said.

The White House on Tuesday said Clinton appeared to have operated in violation of “very specific guidance” from the West Wing that members of the Obama administration use government email accounts to carry out official business.

The House Oversight and Government Reform Committee said it would also look into what its chairman, Rep. Jason Chaffetz, R-Utah, said was a frequent violation of the law. Chaffetz said his inquiry would look at whether Clinton viewed classified or sensitive material on a personal account.

“Do you really believe that the secretary of state never reviewed classified information on her email?” Chaffetz said.

A State Department spokeswoman said this week there was no indication Clinton used her private email for classified information.