In late 2006, as the Australian writer and director Ben Lewin was researching material for a sitcom idea about a person who trades his disabled parking sticker for sexual favours, he came across an autobiographical article entitled ‘On Seeing a Sex Surrogate’, by the American poet and journalist, Mark O’Brien.

Like Lewin, O’Brien had contracted polio in childhood. But O’Brien’s entire body was paralysed, except for one muscle in his right foot, one in his neck and one in his jaw. He was 140 centimetres tall and weighed just 27 kilograms. He existed in an iron lung, except for the few hours a day when he became an odd but familiar sight on the streets of Berkeley, California, cruising the footpaths in an electric, plastic-encased gurney. He steered using a mouth mechanism and mirrors, and at one point manoeuvred it onto a stage to graduate from Berkeley’s School of Journalism.

In 1986, at the age of 36, O’Brien decided to lose his virginity with Cheryl Cohen Greene, a ‘sex surrogate’. As distinct from prostitutes, sex surrogates work with clients suffering sexual dysfunction in consultation with a referring psychoanalyst, and are bound by a code of ethics. Cohen Greene employed a technique developed by the 1960s sex gurus, William Masters and Virginia Johnson. Over six sessions, the client and the therapist would progress from lying together naked, to physical intimacy, to intercourse.

Lewin connected with the honesty of O’Brien’s account. “It was quite immediate,” he remembers. “It really didn’t take a lot of thinking. I printed it out and showed it to my wife, as well as another friend, to get an idea of how big the story was, how far it reached. I got the feeling it did reach most people in the area of fear of sex, which I think is universal.”

Lewin walks with callipers and stands 155 centimetres tall. “Of course there is a commonality of experience. We both understood the impact on parents, what it’s like to feel different, what it’s like to feel isolated, and that yearning for closeness, intimacy. That desire to have a lover.”

 But he doesn’t wish to overplay the connection. “From a marketing angle, it adds some extra interest – that I had polio as well. It gives my take on the story that little bit more credibility. But I didn’t have to struggle for independence in the same way Mark did. There’s a point at which there is a shared experience, and there’s a point of departure. In the end, this story grabbed me in the way that it seems to grab a lot of people – it’s about an amazing man who lived an amazing life.”

Lewin, who is 65, has been in Hollywood writing and directing since 1994. At one stage he supplemented his income by selling antique watches, only to later direct a documentary, Hollywood Gold, about his misadventures in the Beverly Hills jewellery trade at Oscars time.

Lewin swiftly optioned O’Brien’s story and commenced on the script in 2007. His wife, Judi Levine, jumped on as producer. By late 2009, a draft landed in the hands of Ronnie Yeskel, the woman who cast Pulp Fiction. “When Ronnie started sending the script around town, people sat up and listened,” Lewin recalls. Eighteen months later, the ex-barrister from Melbourne – best known here for The Dunera Boys and A Matter of Convenience, and for TV stints directing SeaChange and Ally McBeal – found himself at the helm of a film starring Helen Hunt, John Hawkes and William H Macy.

In signing Hunt, Lewin had to convince the Oscar winner to spend a good chunk of the film naked. The shoot lasted four weeks. “I rarely enjoy making a movie. Usually it’s hell, but this time the script was right, we had terrific actors and a first-class cameraman. All I had to do was not screw it up.”

Still, Lewin and his wife weren’t exactly brimming with confidence. “It was the last roll of the dice for us,” reflects Judi Levine. “We had our dogs vaccinated; we were on the verge of coming back to Australia.”

The Surrogate (since retitled The Sessions) premiered in January at Utah’s Sundance Film Festival, in front of 1300 people. Afterwards, the Variety reporter tweeted: “Standing ovation after The Surrogate premiere at #Sundance. If it were running in this year’s Oscar race, The Artist would be toast.” The film won a jury prize for best ensemble acting, and the audience award for best film. After a frantic four-way bidding war for distribution rights, Fox Searchlight executives signed Lewin and Levine in their Park City condo, at 1 am on the night of the premiere.

The deal, rumoured to be worth $6 million, assured the film of a worldwide release – it opens in Australian cinemas next month. It also instantly opened a lot of doors for the father of three. As he said to Levine later that night in Park City, moments before finally falling asleep, “Darling, I think we can buy some new shoes for the children now.”