David Suchet has told of the lengths he went to in order to perfect Hercule Poirot's distinctive walk when he first took the role.
The actor, 67, said he wanted to get right his character's "rapid, mincing gait", as described by Poirot's creator Agatha Christie.
Suchet, who plays the famous detective for the last time in ITV's Curtain: Poirot's Last Case later this month, told the Radio Times: "I took that (Christie's) description and I practised and practised and practised.
"Laurence Olivier, when he was playing a fop in a Restoration play, wanted to mince ... and famously he put a penny in the crack of his bottom and walked and wouldn't let it drop. If you do that, you can't walk fast, so I did the same thing."
Asked whether he had to use the penny trick for the last 24 years, Suchet replied: "No, but what I made myself do when I wanted to walk like Poirot was to squeeze my bottom.
"That makes you walk with short strides and that's all I do. If you think of Poirot and how he walks - that precise little thing is very much who he is. He is not a man of broad, relaxed gestures."
Suchet said it was emotional saying goodbye to the mustachioed detective after so long in the role.
"I quite openly admit that doing Poirot's final scene was the hardest day's filming of my career . And it was hard because that is the end ... for me," he said.
"I know there's going to be a new book (written by Sophie Hannah) so that's going to be strange to see him resurrected - depending on where she places him. But that will probably be it for me."
Suchet, who said he was about to accept a job offer to become a junior manager at menswear store Moss Bros when he was called to say he had been offered a small role in The Protectors, said he had never forgotten what it was like "to be broke" before his acting career took off.
"If you've got nothing, they say there's nothing to worry about. But not in our society. If you've got nothing, there's plenty to worry about.
"Those who haven't anything are very aware they haven't and it's very, very hard for them and it was very hard for me and it was very hard for my wife," he added.