Immunity granted to Hillary Clinton staffer who set up server: Report

Bryan Pagliano, who worked on Clinton's presidential campaign in 2008, had previously invoked his constitutional right to silence

Hillary Clinton's former staffer who helped set up the controversial private email server she used while secretary of state has been granted immunity in a criminal investigation into the affair, a media report has said.

The US Department of Justice granted immunity to Bryan Pagliano, who set up the server in 2009 and is now cooperating with the FBI, The Washington Post reported yesterday, citing a senior law enforcement official.

Pagliano, who worked on Clinton's presidential campaign in 2008, had previously invoked his constitutional right to silence when asked to answer questions about the matter before a US House Committee in September.

Clinton, the Democratic frontrunner in the 2016 US presidential election, took a big leap toward clinching her party's nomination Tuesday during primaries across 11 states, in which she racked up seven wins, trouncing rival Bernie Sanders.

Clinton snagged those states and has gained recent momentum despite the cloud of the email scandal still looming over her campaign. When it emerged last year that she had used a private server and non-official address for all her email while in her former post as secretary of state, her Republican rivals cried foul.

This, they said, suggested she may have been illegally covering something up.

But Clinton maintained that none of her emails had been marked "classified" when she sent them and, after her own lawyers had removed mails they deemed purely personal, she submitted a 52,000-page document dump to the State Department.

Officials will likely want to interview Clinton and her senior aides about the server when the FBI concludes its probe in several months, The Washington Post said, citing current and former officials.

The State Department has been making the official emails public chunk by chunk, and released the final batch on Monday.

The email scandal is one of the few major hitches in Clinton's otherwise very promising campaign to become the 2016 Democratic presidential nominee.