Hillary Rodham Clinton’s attorney has provided the FBI with the private server that housed her e-mail during her four years as secretary of state, Clinton’s presidential campaign said Tuesday.

Her attorney also gave agents a thumb drive containing copies of thousands of e-mails that Clinton had previously turned over to the State Department.

The FBI has been looking into the security of Clinton’s unusual private system, which has emerged as an issue in her campaign.

Nick Merrill, a Clinton spokesman, said Tuesday night that Clinton is cooperating with the probe. He declined to say whether the FBI ordered that she turn over the devices and when they were turned over.

“She directed her team to give her e-mail server that was used during her tenure as secretary to the Department of Justice, as well as a thumb drive containing copies of her e-mails already provided to the State Department,” Merrill said. “She pledged to cooperate with the government’s security inquiry, and if there are more questions, we will continue to address them.”

The inquiry by the FBI is considered preliminary at this point and appears to be focused on ensuring the proper handling of classified material.

The agency’s efforts included contacting the Denver-based technology firm that helped manage the Clinton’s unusual private e-mail system.

Clinton has resisted relinquishing control of the server. In March, she said the server contained “personal communications from my husband and me.”

“I believe I have met all of my responsibilities, and the server will remain private,” she said then, in response to a question from a reporter about whether she would allow an independent party to examine the device.

Also that month, her attorney David Kendall told a congressional oversight committee in an e-mail that there was “no basis” to support a third-party examination of the server. He indicated that he had confirmed with IT staffers that no e-mail sent or received by Clinton’s account while she was secretary of state remained on the server or backup systems associated with the system.

“Thus, there are no hdr22@clintonemail.com e-mails from Secretary of State Clinton’s tenure on the server for any review, even if such a review were appropriate or legally authorized,” he wrote.