Libertarian vice presidential candidate Bill Weld said there may be nothing in the new emails uncovered by the FBI.

"Well, you know, I think there's less there than meets the eye," Weld said Monday on CNBC's "Closing Bell."

On Friday, FBI Director James Comey said in a letter to lawmakers that the bureau is looking into recently uncovered emails related to its investigation of Hillary Clinton.

Weld, a former Massachusetts governor, explained that Comey may have felt obligated to send the letter because he testified to Congress that he'd update lawmakers on the investigation.

"I think he had a bad hair day when he decided to send them that letter last Friday. Nothing more than that," Weld said.

Weld, a former federal prosecutor, said Comey's letter was "not enough" because "there's no evidence that there was any evidence there." He added that he supported the FBI's decision to not recommend charges against Clinton in July because he felt there was no evidence of criminal intent.