WASHINGTON - Hillary Rodham Clinton wiped her e-mail server "clean," permanently deleting all e-mails from it, the Republican chairman of a House committee investigating the 2012 Benghazi attacks said Friday.

Rep. Trey Gowdy (R., S.C.) said the former secretary of state has failed to produce a single new document in recent weeks and has refused to relinquish her server to a third party for an independent review, as Gowdy has requested.

Clinton's attorney, David Kendall, said Gowdy was looking in the wrong place.

In a six-page letter released late Friday, Kendall said Clinton had turned over to the State Department all work-related e-mails sent or received during her tenure as secretary of state from 2009 to 2013.

"The Department of State is therefore in possession of all Secretary Clinton's work-related emails from the [personal e-mail] account," Kendall wrote.

Kendall also said it would be pointless for Clinton to turn over her server, even if legally authorized, since "no emails ... reside on the server or on any backup systems associated with the server."

Clinton, a likely Democratic presidential candidate, faced a Friday deadline to respond to a subpoena for e-mails and documents related to Libya, including the 2012 attacks in a U.S. diplomatic compound in Benghazi that killed four Americans, including the U.S. ambassador to Libya.

The Benghazi committee demanded further documents and access to the server after it was revealed that Clinton used a private e-mail account and server during her tenure at the State Department.

Gowdy said he will work with House leaders to consider options. Speaker John A. Boehner has not ruled out a vote in the full House to force Clinton to turn over the server if she declines to make it available by an April 3 deadline set by Gowdy.