Andy Serkis praised the family of the late Ian Dury, saying he could not have played the musician in new biopic Sex & Drugs & Rock & Roll without their help and support.
The Lord Of The Rings star hosted a special screening of the film at the Screen On The Green cinema in Islington where he was joined by the cast of the film, star guests including Coldplay's Chris Martin and Dury's friends and family.
Serkis said: "It wasn't daunting because we had so much help from Ian's family, all the time we had them at our shoulder and they really helped to inform the whole process really.
"But I've always felt very close to Ian's take on things and the way he thinks about the world, so I suppose I felt quite in tune with it."
But the 45-year-old actor said having Dury's widow Sophie and his son Baxter present on set, along with members of the Blockheads, did feel like added pressure at times.
He said: "I remember once when we were shooting at Vauxhall Palace, we were shooting the live concert bit and that was quite nerve wracking because Sophie came up and adjusted my scarf. Ian used to tie his scarf in a very particular way and Sophie came up and adjusted my scarf just as I was about to do the opening number. That was particularly nerve wracking because it suddenly brought sharp relief that they were there watching."
Serkis met the Blockheads' frontman before his death from cancer in 2000 and has described him as an "obnoxious" character.
He said: "The beauty of Ian as a character is that he's a million different things to different people and that was brought out by talking to his family, because he could be very sweet and gentle and very loving and compassionate and then he'd flip like a coin and be very visceral and nasty.
"But that came from being a very creative, driven man who got beaten around and loves to demonstrate and feel all those things. And yes, when I met him he wasn't particularly nice."
Director Mat Whitecross also praised the family for their help and support, saying that when they were sent the first draft of the script they were unhappy with it as they felt it did not show how truly "nasty" Dury could be.