There are numerous examples in the various film industries for the films which were completed after one of the actors passed away unexpectedly in the middle of the filming, some of them are:
Sanjeev Kumar:
The renowned Bollywood actor Sanjeev Kumar had passed away suddenly due to heart attack in 1985 at the age of 47 years, in the middle of the filming of the comedy film Professor Ki Padosan.
The 75% of filming was completed, Ravi Tandon was directing the film but due to film's leading actor Sanjeev Kumar's demise he left the project and Shantilal Soni took incharge to direct the film. The makers had to rewrite the storyline to make his character invisible in the remaining portions of the film and the film was released in 1993. Sudesh Bhosle dubbed Sanjeev Kumar's remaining dialogues. Shekar Suman and Dalip Tahil were added in the film after Sanjeev Kumar's death. Amitabh Bachchan narrated the film and he paid tribute to Sanjeev Kumar in the last scene of the film. Asha Parekh and Padmini Kolapure also acted in the leading roles.
Shyam:
During this time the most noted actors were Ashok Kumar, Dilip Kumar and Shyam was lesser popular when compared to them as he passed away at an early age.
1950s actor Shyam lost his life during the shooting itself, unfortunately during the filming of film Shabistan, he fell down while riding the horse in an action sequence, he got a serious head injury and he passed away at the age of 31 years in 1951.
His final scenes were completed by using body double with a similar height and filmed from a distance in the dark. The film had totally 8 songs, Naseem Banu was the leading actress, actors like Murad, Cuckoo, Helen & others acted in the film and Bibuthi Mitra directed the film.
Rishi Kapoor:
Rishi Kapoor had passed away during the filming of Sharmaji Namkeen due to his illness in 2020, later actor Paresh Rawal completed his remaining scenes.
This became the first example in Hindi film industry of two actors performing the same character simultaneously. Juhi Chawla, Satish Kaushik, Sheeba Chaddha and others acted in the film. The film received positive response for performances and direction, especially Rishi Kapoor widely got praised for his good acting.
Malayalam actor Krishnan Nair or popularly known as Jayan died in 1980 in a tragic way during the filming at the age of 41 years.
During the shooting of the climax scene of the film Kolilakkam, he was performing a dangerous stunt scene of boarding an airborne Bell 47 from a moving motorbike driven by Sukumaran. The director accepted the shot in the first take but Jayan was not satisfied and he asked for re-take. During the re-take the helicopter lost its balance and it crashed down alongwith Jayan who was hanging on to the landing skids, due to serious injuries he lost his breath.
Jayan is considered as the first and the most successful action hero of the Malayam Cinema.
This action thriller film was completed by using body double for the remaining few scenes of Jayan and mimicry artist Alleppey Ashraf dubbed his dilalouges. The film was released in 1981, P. M. Sundaram directed the film, alongside Jayan, Madhu and Sukumaran acted in the film. It was box office hit and the remake of Hindi film Waqt.
Divya Bharti:
Regarding this actress most of the people are very much aware of, Divya Bharti died in a tragic way in 1993 at the age of 19 years by falling from the balcony of her 5th floor apartment. At that time she was signed and was acting in several films and she was replaced by other actresses.
During that time she was also filming for Telugu film Toli Muddu alongwith Prashant, after her sudden death, actress Ramba who slightly resembled Divya Bharti completed her remaining scenes and Roja Ramani dubbed her voice. The film was released after 6 months of her demise and it was the remake of Hindi film Dil, it was a commercial hit and was also dubbed in Tamil as Ilan Nenje Vaa.
So, the above are the actors whose films got completed even after their unfortunate demises in the middle of the filming. Most of them had passed away at an young age and their untimely demise had become a big loss for the particular film industries.