David Suchet has admitted it was harder to return to the role of Poirot than he thought it would be, and said he studies his previous performances for hours.
The 67-year-old actor has played Agatha Christie's famous Belgian detective Hercules Poirot for 25 years in the ITV adaptations of her stories, and has just completed filming the last five, to air on television this year.
Suchet revealed: "It is always more difficult than I ever imagine it will be for two reasons. I do so many things in between and play so many different characters, but also because Poirot is so particular and so precise. Agatha Christie was famous for never changing his character.
"Although the scripts allow me some development, every time I come back to Poirot I have to come back to his voice, his walk, and his mannerisms. What I always think is going to be an easy glove to fit again, it's always very hard. I usually have to watch up to ten hours (of previous footage) prior to filming and then practise getting the voice correct so that I match exactly, apart from natural ageing and things like that.
"Viewers should be able to see from 25 years ago to now that the character himself is still there and hopefully hasn't changed and is the Agatha Christie character from day one."
The actors is also associate producer on the series.
He said: "Everyday I'm on the set I can always have an input if I see things that are not going quite right. Cast and crew can also come to me with a problem if our producer is not available.
"I like it very much because I'm the only one really that's been there from the beginning so I can be very useful and helpful hopefully."
::Elephants Can Remember is the first of five new Agatha Christie adaptations to screen on ITV.