The Republican chairman of a US House of Representatives committee investigating the 2012 Benghazi attacks has said that former Secretary of State Hillary Clinton failed to respond to the panel's subpoena for documents in the case.

Representative Trey Gowdy said on Friday that Clinton had not provided a single new document and her lawyer told the committee a server she used for emails while she was the top US diplomat had been wiped clean.

"We learned today, from her attorney, Secretary Clinton unilaterally decided to wipe her server clean and permanently delete all emails from her personal server," Gowdy, chairman of the House Select Committee on Benghazi, said in a statement.

He said the committee will seek to speak to Clinton, the presumed frontrunner for the Democratic presidential nomination in 2016, about the emails and the server.

Clinton, who was sharply criticised after it was revealed she used a private email address while secretary of state, has said she has already given copies of all her work-related emails to the State Department.

Clinton has told the committee and the State Department that she would like all her emails made public as soon as possible and welcomes the opportunity to appear before the House panel, Clinton spokesman Nick Merrill said in a statement.

The State Department has said it has already given Gowdy's committee all the relevant emails from that cache, some 300 in all, about the attack on the US diplomatic compound in the Libyan city.

Members of Gowdy's committee say they need to see all of Clinton's emails, including those she did not give to the State Department, to be sure of this.

But the top Democrat on the committee, Representative Elijah Cummings, said the letter the panel received from Clinton's lawyer confirmed that Clinton had turned over all relevant emails.

"It is time for the Committee to stop this political charade and instead make these documents public and schedule Secretary Clinton's public testimony now," Cummings said in a statement.

Source: Reuters