The release of the new Kevin Kline and Dakota Fanning movie The Last Of Robin Hood will be bittersweet for writer/director Wash Westmoreland - because the woman he spent years tracking down and then persuading to let him adapt her love story didn't live to see it.

After reading Tedd Thomey's book, The Big Love, about Beverly Aadland's romance with silver screen icon Errol Flynn in 2003, Westmoreland attempted to track down the forgotten actress and singer.

Thomey made the introductions and the director drove to Palmdale, California to meet the reclusive former socialite.

He tells Wenn, "We really wanted to get in touch with Beverly but she was famously guarded about the story. We wrote a very nice letter and waited. A few weeks later we got a phone call from Mr. Delvin Irwin from Mississippi saying, 'I hear you want to talk to Woodsy,' which was Flynn's nickname for her; he (Delvin) was a Flynn fanatic who had made friends with Beverly and her husband Ron and was kind of acting as a gatekeeper.

"We met her in a Mexican restaurant and she came in with her husband. She was very friendly but didn't put all her cards on the table at first. It was personal to her and she felt very bruised about the way that the romance has been treated over the years. She resented her mother stealing her story and teaming up with Tedd Thomey for The Big Love."

But Westmoreland's research impressed Aadland and her husband - he even tracked down a recording of Beverly singing Some Say two months after Flynn died for the film - and she agreed to let him make the movie.

He adds, "That's actually a real Beverly Aadland song. We managed to get the rights and we got Ron and the couple's daughter in the audience for the cabaret scene, where Dakota (Fanning) performs.

"Ron, who is a salt of the earth American blue collar guy, was just incredibly moved and was in tears watching this. He was just incredibly proud and the only sadness was that Beverly couldn't be there. She died in 2010. We always promised her the film would get made but she never saw it on the big screen."

The movie also features a cameo from Sean Flynn, Errol's 23-year-old grandson.

Westmoreland explains, "He played the guy who Beverly goes off with in Cuba on the back of the motorbike. So Kevin (Kline), as Errol, gets to look out the window seeing them disappear off into a cloud of dust, where he's really looking at Errol Flynn's grandson taking his girl away!

"He (Sean Flynn) said, 'People of my age don't know who Errol Flynn is', and he never met him. So when he met Kevin Kline as Errol, he said, 'I feel like I finally met my own grandfather'."