Royal Bengal Rahashya (Bengali: রয়েল বেঙ্গল রহস্য) (2011) is a thriller film directed by Sandip Ray based on the novel of the same name by Satyajit Ray. The film was released on 23 December 2011. It is the fifth and the final installment of New Feluda Franchise and the sequel to Gorosthaney Sabdhan. After the demise of Bibhu Bhattacharya (Jatayu), Sabyasachi Chakrabarty declared that he would not be playing Feluda anymore. Thus, director Sandip Ray decided to reboot the series, Badshahi Angti (film), the first installment of which starring Abir Chatterjee as Feluda and Sourav Das as Topshe was released on 19 December 2014.
On an invitation by Mahitosh Singha Ray, Lalmohon Babu robs Feluda and Topshe at a forest near Bhutan and climbs up in the ancestral home of Mahitosh Singha Ray. After few days of their arrival,Mahitosh Singha Ray's assistance, Tarit dies. His deadbody is found in the forest, and police believes he has died due to the tiger's snarl. But later they found a blood-stained sword near his body. Meanwhile, Mahitosh gives Feluda a puzzle to solve. Feluda's amazing intelligence is proved in this part. He solves it most amazingly, and at the end, chalks out that a treasure chest is hidden 55 hands away from a tree which has a hole between it, which looks like an old person's mouth without any teeth; between two Arjuna trees. While Feluda and his companion are on the way to the treasure chest, they finds Tarit's spectacles and later on, his torch, which suggests that Tarit has solved the puzzle much earlier than the others, and was on his way to the treasure chest. At last, Feluda finds the treasure chest, and helds out the conclusion. Mahitosh had broke his hand due to a fall from a tree, which Feluda came to know when he was unable to hold the rifle. All the precious huntings of the tiger were done by his friend, Shashanka. On that night, while Tarit was about to leave, Shashanka too followed him quietly. When there came a Royal Bengal Tiger. Shashanka fired his rifle, which shoot off the tiger's nose after Feluda found a bit of skin. Tarit's sword, as he observed, has begun acting like a magnet, which was created by a flash of lightning. Thus, Tarit wasn't murdered by any villain, but only, the nature was the cause of his death. He, at the end of the story is rewarded with a part of treasure.
The film version of the book was made by Sandip Ray with the earlier cast of the leading characters. The opening credits include a note that all the animals that appear in the film have been fashioned digitally. The actor of 'Jatayu', Bibhu Bhattacharjee died on the night of 22 September 2011, the day the dubbing was completed. It was released on 23 December 2011. The film is produced by Shree Venkatesh Films and Surinder Films. The film, made on a budget of 2 crore grossed about 3.00 crore, became a Superhit.