Keddie and Wenham find trust in their collaboration on Aussie thriller Fake

So deep, in fact, he had to truly believe that the world Joe Burt had created for himself was his own misguided truth.

"He's a fascinating guy because you describe him as a fantasist, somebody for who there is no distinction between fantasy and reality - none whatsoever," Wenham said.

"I don't think he has any comprehension of the effect of what he has upon those people. I don't think he's aware of the negative effects of what he does, which is sort of interesting.

"It was the only way I could go about it. Literally every scene of that character was played truthfully in that moment because, from my standpoint, that's probably what he did."

Fake places Wenham in a role long-term fans of the Sydney actor will find hard to recognise.

The 58-year-old Order of Australia member is best known for playing "heart-throb" Diver Dan in late '90s hit TV show SeaChange and for his performance as the reluctant hero, Faramir, in Lord Of The Rings.

But Joe is the worse of manipulative and emotionally abusive lovers.

"I spoke to a psychiatrist and a psychologist about this type of character, which was quite fascinating," Wenham said. "Essentially if you stepped back and were objective about him, he does suffer from a personality disorder.

Joe Burt is based on a real-life man Sydney Morning Herald journalist, Stephanie Wood, once dated before discovering the entire world he constructed - his job, relationship status, and family - was a complete fabrication.

Wood's Good Weekend article about her experience was later expanded into the memoir, Fake: A startling true story of love in a world of liars, cheats, narcissists, fantasists and phonies.

The story struck such a chord that Wood was contacted by hundreds of women and men with similar stories about fake relationships.

Fake is likely to create similar discussions around online dating and relationships, particularly with one of Australia's most popular actresses, Asher Keddie, playing the victim of Joe's lies.

Keddie plays Birdie Bell, a food journalist, loosely based on Wood. Birdie is a 40-something woman who is increasingly under pressure to find love from her family and friends.

After initially rejecting Joe's advances on an awkward first date, she slowly becomes infatuated with their love affair, which begins in unravel her mental health.

The five-time Logie Award-winner for Most Popular Actress is best known for roles in Love My Way, Offspring and Paper Giants: The Birth of Cleo, but becoming Birdie involved embracing new depths of vulnerability.

Keddie said it was a challenging role made more comfortable by having Wenham as her co-star.

"With such brutal content, it does become very challenging, the show as you go along," Keddie said.

"It was such a relief and a pleasure to work together knowing there was a great deal of trust.

"If it hadn't been there, because relationships don't always work when you're working together, this would have been a mighty tricky show to shoot.

"But it wasn't. It was a joy, if you can say that about making something like this."

Keddie, who is also a co-producer on Fake, read Wood's book but avoided meeting her until the production of the eight-part series was well developed.

Keddie said she wanted Birdie to be her fictional interpretation of Wood, not the journalist herself.

"I made that choice, and I have done that in the past with books that have been brought to the screen or stories that are inspired by true stories," she said.

"It was more for me about interpreting this character who we made fictional, in a way I could understand her and her impulses and her vulnerabilities and her choices.

"That's how you try to bring as much authenticity as you can to a role.

"I didn't speak to Stephanie. I drew so much from the book, as we all did, and her experience with this guy and what this turned into for her realising it was a very common situation for many many people."

Trust is central to Fake and how blindly we place it in other people.

"What was interesting for me, as humans, our default position so we can actually operate as a functional community, is to actually trust one another," Wenham said.

"When that trust is taken away, it can be a devastating thing. I suppose it goes to illuminate how little we know somebody, other than what they tell us."

Both Keddie and Wenham expressed relief that they were both in long-term relationships prior to the rise of online dating, which they describe as "a minefield."

They both agree that Fake isn't a "didactic piece" served to educate people to the pitfalls of online dating. Rather, they hope it entertains and creates conversations.

"You're really inside the journey of both people. So I think it'll be relatable and I hope that it is," Keddie said.

"I hope it offers that, as well as being a compelling piece of drama. We're not ramming any one thing down anyone's throat. It's not like that. It's not that kind of piece. You contemplate. You think about it and it ignites different feelings."

Fake is streaming now on Paramount+.