Michael Turnbull has defended his controversial new business venture.

A Current Affair has accused Bachelorette star Michael Turnbull of trying to convince his followers to “sink their cash” into a controversial new product he’s bringing to Australia.

The Channel 9 program tonight aired a ‘special investigation’ into the 35-year-old’s involvement with Nerium, an anti-ageing skincare brand that’s attracted criticism overseas.

ACA alleged the brand had previously been accused of operating like a pyramid scheme, doctoring before-and-after photos to exaggerate its effectiveness, and even faking a celebrity endorsement by actor Ray Liotta.

While Turnbull denied any association with the company during the August 11 interview, he later confirmed his involvement via a video posted to social media, telling his followers that he had “been asked to put together a strong, motivated entrepreneurial team to help spread the word in Australia.”

The brand is yet to have its official local launch and its Australian business plan remains unclear, but as ACA claimed, the Nerium name has been dogged by accusations that it operates via a pyramid-like structure overseas.

These accusations, which have been denied by the company’s CEO, Jeff Olson, were put to Turnbull on tonight’s episode.

“I certainly wouldn’t intentionally get into a pyramid scheme, if that’s what this business is. I certainly wouldn’t be out to rip people off or take their money,” he said.

“People can make their own decision and do their own research. If they decide to do something, that’s their call. I just give them an opportunity.”

Turnbull denies Nerium is a pyramid scheme. Image: Channel 9.

In the social media video posted earlier this month, a ticked-off Turnbull also lashed out at ACA for “ambushing” him with the allegations.

“A Current Affair are at it again, as they love to do with me. It’s my third time now so I’m feeling pretty special,” he said.

“I invited them up to my home. I said, ‘You know what, guys, we can do this weird, crazy, stalker, coward interview, you know the way ACA do interviews, or we can do it here’,” he said.

Slamming the show's criticism of a "legitimate business", Turnbull told his followers, “I don’t support pyramid schemes in any way, shape or form.

“If you see the stuff on A Current Affair, it’s edited to look like I have no idea what I’m doing, I’m ripping people off, and that’s certainly not the case. I’m all about transparency.”

It's unclear how much money Turnbull stands to make from the venture.