A young supporter of Donald Trump has launched an extraordinary defence of the Republican candidate's “grab her by the pussy” comments.

The Trump campaign was rocked last month after a 2005 recording of the candidate's crude, sexually explicit comments about women were released online.

The comments provoked a strong backlash - including from Democratic candidate Hillary Clinton - and led to the usually unapologetic Trump releasing a video apology.

More than a dozen women have since come forward to accuse Trump of sexual misconduct - although he has denied the claims in the strongest terms.

The release of the recording saw support for Mr Trump drop in opinion polls and led to numerous Republican politicians withdraw their previous endorsements.

However, one supporter told Newstalk reporter Shona Murray that he doesn't know "what the problem is".

The 27-year-old from Pennsylvania - who only gave his first name as 'Justin' - said: "I wouldn't call it harassment if there was consent. He said the words 'they let you do it' - I don't know about you but the word 'let' implies consent.

“This whole 'oh, he's a sexual predator' is nonsense because when you’re a billionaire, obviously you’re going to have more opportunities with the opposite sex. I mean who's going to deny that? It's just common sense."

Justin argued that Trump “saying the obvious” in a personal setting when he didn’t know he was being recorded "doesn't surprise him at all", adding that he doesn't know what people "are so shocked about or offended by [...] I'm pretty sure everyone on planet Earth has heard someone talk that way".

When quizzed by Shona about whether it's reasonable for the president of the US to say something like Mr Trump's remarks, Justin responded: "Do you have a problem with Donald Trump being a heterosexual male? I'm pretty sure every man who is straight has grabbed someone by the pussy at some point or another."