Showing her uncanny sense of humour, Democratic presidential frontrunner Hillary Clinton declared in an interview on Sunday that she is actually a "robot."

Clinton made the remark during the BuzzFeed podcast "Another Round" in response to a question on why she was not sweating during the interview.

Reporters covering her campaign and even her associates have long wondered why they have not seen Clinton sweat during her hectic campaigning even during hot days, Vanity Fair reported.

Podcast host Tracy Clayton asked her why she does not seem to sweat. "I don't mean sweat because you're nervous. I just mean physically. I'm genuinely curious what your deodorant is," she asked.

Clinton's then replied: "You guys are the first to realise that I'm really not even a human being. I was constructed in a garage in Palo Alto a very long time ago. People think that, you know, Bill Gates and Steve Jobs, they created it. Oh no. I mean, a man whose name shall remain nameless created me in his garage."

Q: "Are there more of you?"

Clinton: "I thought he threw away the plans, at least that's what he told me when he programmed me — that there would be no more. I've seen more people that kind of don't sweat, and other things, that make me think maybe they are part of the new race that he created: the robot race."

Q:: "So there's a cyborg army is what you're saying."

Clinton: "But you have to cut this, you can't tell anybody this. I don't want anybody to know this. This has been a secret until here we are in Davenport, Iowa, and I'm just spillin' my electronic guts to you."

Q: "And without bourbon."

Clinton: "Without any bourbon. Yeah. That's why I have to wait 'til the end of the day."

The joke appeared to be Clinton's attempt to "humanise" herself, according to the Daily Mail.

Earlier this month, Clinton appeared on "Saturday Night Live" for the first time and played a bartender named Val. She got positive response for her comedic act, with daughter Chelsea Clinton leading the applause. "I think my mom's really funny," she said. "And I'm grateful that America is seeing more of that."

Hillary still the Dem bet to beat

Meanwhile, on the eve of the Democratic Party's first presidential debate at CNN on Tuesday night in Las Vegas, Clinton remains the candidate to beat, according to pundits based on the fact that she remains way ahead of her rivals in voters' surveys.

"Hillary remains formidable," investigative journalist Ed Klein told WND in an interview. Klein is the author of the recently published bestseller, "Unlikeable: The Problem with Hillary."

Klein believes Clinton will weather the scandals that are hounding her campaign. On top of the continuing email controversy, there is renewed interest on husband Bill Clinton's sexual exploits during his time at the White House aside from the allegations about Clinton Foundation financial crimes.