In Agatha Christie's Poirot, she was portrayed by Jacinta Mulcahy.
Bella Duveen was a stage performer from London, with whom Jack Renauld was secretly in love (despite having a relationship with Marthe Daubreuil), and the twin of Dulcie Duveen.
After Jack was arrested by Monsieur Giraud for being a suspect of his father's murder as well as the accidental death of an unnamed tramp, Bella falsely confessed to the murder in exchange of Jack's release. She revealed to Poirot and Hastings that she had come across the body of the said tramp and witnessed his death by epileptic fit, something she took responsibility for saving Jack and faking that the tramp was murdered by her.
However, Poirot managed to discovered the true identity of the culprit, who was actually Marthe Daubreuil, making both Bella and Jack to be released.
After everything was settled, Bella married Jack who decided to reform himself, and moved to South America alongside his family for a trip, whilst her sister Dulcie had married her love interest, who was none other than Captain Arthur Hastings.
- In Agatha Christie's Poirot, her role as Hasting's lover and wife was taken from her twin sister, Dulcie Duveen, who was omitted from the narratives. Here, Bella had dumped Jack for his infidetily and married Hasting under Poirot's advice.
- In the final episode, Bella was mentioned to be passed away by Hastings, whilst in the original novel it was still her sister Dulcie who passed away. In the novels, Bella was never mentioned again after her only novel appearance.