Eddie Redmayne shrugged off growing excitement he is in line for a second Oscar for his role as one of the first transgender women.
The star, who scooped the best actor Academy Award for his performance as Stephen Hawking in The Theory Of Everything, described his latest film, The Danish Girl, as "one of the great love stories of the 21st Century".
Wearing a red tartan suit Redmayne braved biting temperatures on the red carpet for the film's London premiere, alongside co-star Alicia Vikander, who plays Lili Elbe's wife, Gerda.
Speaking after greeting fans in Leicester Square, the 33-year-old declined to speculate on his chances of winning a second year in a row, but described filming as "wonderful experience".
He said: "Getting to play her was one of the most wonderful presents, I just thought her and Gerda's story - I couldn't believe I hadn't heard it before. I thought it was one of the great love stories of the 21st century, it was the most wonderful experience getting to play her."
Redmayne has been tipped for Oscar's success for his performance in which he portrays Elbe's transition to become a woman.
The Danish artist became one of the first people to undergo gender reassignment surgery in the early 1930s.
While researching the film, directed by Tom Hooper, who is best known for Oscar winner The King's Speech, Redmayne spent a year with the transgender community and delving into Elbe's life.
He said: "For me it was about trying to work out who Lili was, there was a book published after her death of her diary entries and finding out about finding out who she was and working back from there into who she was when she was living with this construct about masculinity around her, who she was when she was living as a man.
"The whole film has been just a wonderful education for me and I've learned a huge amount."
Redmayne said accepting the role came with "great responsibility" and he was left "sucker punched" by the script.
He paid tribute to Vikander's "volcano of talent" and described the Ex Machina star as "magnificent", but replied "God, no, don't do that," when asked if the film had Oscar potential.
The 27-year-old Swedish actress said it was "incredible" how deeply Redmayne became invested in the character.
She added: "I was blown away when I did my first reading with Eddie and he's pretty extraordinary in this film. To see the sensitivity he has in his journey throughout is remarkable."
Redmayne had dedicated a huge amount of personal time to developing the character before they got on set, the actress said.
"Before this film I had not put so much thought into gender as a subject but what I realise is I find it so fluid after spending time with people from the transgender community and the LGBT community."
The film's British director stormed the Academy Awards in 2011 with The King's Speech, winning four Oscars.
Several directors were said to have been slated for The Danish Girl, although the film took several years to secure funding before Hooper picked up the baton.
The director said: "I fell in love with this extraordinary love story seven years ago, at that time it was considered a hard film to make, maybe risky, a difficult film to finance, but to see how it has been embraced shows how far we have come as a culture, there's been a great shift in terms of the popular acceptance of trans stories and the interest in trans stories and that's fantastic."
On choosing Redmayne to play Lili, the director described him as an "extraordinary actor", who he first worked with in 2005 alongside Dame Helen Mirren in Channel 4 drama Elizabeth I.
The pair last worked together in Hooper's 2012 epic retelling of Les Miserables, when Redmayne took the role of Marius.
He said: "Eddie's very emotionally connected which is exciting and it was on the barricades of Les Miserables I handed him the script in a brown paper envelope and said 'please read this I would love you to do it'.
"He came back the next morning and said 'I am in love with this script like you were, let's do it'."
Describing Redmayne's on-camera transition, he added: "A lot of the key work was psychological and understanding the psychology of the journey from the inside out. We tried various things but it was when we chose the simplest look that Lili came alive and Eddie relaxed most."