When Jodie Comer gave an emotional acceptance speech at last weekend’s Bafta awards, the star of Killing Eve singled out one man, a fellow Liverpudlian actor, for kickstarting her career. “I want to take this moment to thank Stephen Graham,” she said. “If I didn’t owe you a pint before then, I do now. Thank you for the generosity you showed me all those years ago.”

While many in the rapt audience will have wondered what she was referring to, one woman knew: Jane Epstein, Graham’s agent for almost 19 years, and the woman whom he persuaded to take a chance on a young Comer seven years ago.

“Stephen called me from the set of a series he was doing back in 2012 called Good Cop and passionately described a scene he had just shot with a young actress who he thought was one of the most exciting talents he had worked with to date,” said Epstein. “He was so impressed by her and asked if I would meet her. I did, and he was right.”

As an agent, she added, “you just get a gut feeling when you meet someone that you know you want to work with. While Jodie was very young [Comer was in her late teens] it was nevertheless obvious to me that she had the energy and spirit that would translate on to the screen. That, coupled with the fact that I trusted Stephen’s judgment, made my decision to offer representation to Jodie an easy one.”

In the first episode of Good Cop, a BBC One police procedural shown for one series only, Comer plays a waitress sexually harassed and nearly assaulted in a toilet cubicle by Graham, whose character, a thuggish criminal, soon comes to a sorry end. Over the next five years Comer, now 26, landed a series of increasingly eye-catching roles including My Mad Fat Diary’s spoilt Chloe, Kate the ice-cold other woman in Mike Bartlett’s addictive melodrama Doctor Foster and conflicted former abductee Ivy in Marnie Dickens’s dark and twisty BBC Three series, Thirteen.

Facebook Twitter Pinterest Jodie Comer accepts the Bafta award for best leading actress for her role in Killing Eve. Photograph: James Veysey/Bafta/Rex

She then starred in The White Princess, a glitzy adaptation of Philippa Gregory’s best-selling novel that would prove most notable for the young actress’s charismatic performance as the initially out-of-her-depth Elizabeth of York, before being cast as charming, fashion-obsessed psychopath Villanelle in Killing Eve, for which she won the leading actress award at the Baftas.

At the same time her mentor, Graham, 45, has also built a reputation as one of Britain’s most exciting actors, currently winning plaudits for a bravura turn as an alcoholic haunted by past ghosts in Channel 4 drama The Virtues and recently giving an eye-catching performance as a tormented undercover cop in hit BBC series Line of Duty. The pair are now among Britain’s most in-demand actors, and Epstein is unsurprised.

They both, she said, had the instincts needed to build a lasting career. “It’s extremely hard to build careers in this volatile and fickle business,” she says. “You just have to trust your own instincts when reading a script. Of course there are many factors to take into account, but it all starts with the material.”