The 60-year-old, who gave the Nepali film industry such hits as "Kusume rumal" and "Balidaan", says he was inspired to make the film after a conversation with Buddhist monks from Sri Lanka and other places.
"First, there was this Bollywood movie, 'Chandni Chowk to China', that claimed the Buddha was born in Nepal," Ghimire told IANS in an interview. "Then there are reports of renowned Bollywood director Ashutosh Gowarikar making an epic film on the Buddha.
"We are concerned whether there isn't some political motivation - to lay claim to the Buddha. If Gowarikar builds the sets of Kapilavastu, the kingdom in which the Buddha was born to its ruler King Shuddhodan, the Indian state where it is erected may be regarded by many people as the birthplace of the Buddha.
"Some puzzled Sri Lankan monks actually asked me whether the Buddha was born in India or Nepal. I told them, he was born in Kapilavastu, when neither India nor Nepal existed. Archaeological ruins prove Kapilavastu was in southern Nepal. You can still see the remains of the old palace and the garden where the Buddha was born."
"Gautam Buddha", to be dubbed in English, Hindi, Sinhalese, Korean, Chinese, Japanese and German, is going to be an animated film and the first animated feature film from Nepal.
"It would have cost far less had I chosen people to play the roles," he says ruefully. "But I found that impossible.
The Buddha literature available details minutely the 32 auspicious signs Prince Siddharth possessed, that made him a king among men. He had arms that reached his knees, the large kindly eyes of a cow, and a voice as deep as an echoing well. I realised it would be impossible to find such an actor."
Incidentally, Gowarikar is said to be on a manhunt to find the perfect face for his Buddha. "The Little Buddha", the 1994 feature film made by Hollywood director Bernardo Bertolucci, obliquely presents the story of the Buddha and his
quest for enlightenment, with Keanu Reaves playing the role.
Ghimire's film will be ready by 2013. However, he has a sneak preview for the media in mind later this year when only a few scenes will be shown.
Ghimire says he read all the literature available on the Buddha that he could get, including Dr B.R. Ambedkar's "The Buddha and his Dhamma", and Indian vipassana guru S.N. Goenka's writings about the Buddha and Buddhism.
"There are three schools detailing the Buddha's life," he says. "The Mahayana Buddhists chronicle a logically believable life while the Hinayana Buddhists depict Prince Siddharth as a reincarnation of god. The Vajrayana school, on the other hand, invests him with tantric powers.
"I have tried to adopt a middle path in my story-telling."
Ghimire says his 110-minute film will explode some of the common myths about the Buddha, including the one that said the prince left the luxury of the palace in shock after he saw an old man, a sick man, a dead man and a monk.
"The prince was 29 when he renounced worldly life," Ghimire explains. "It is therefore impossible that he didn't come across any old man in that time. His own father must have been old at that time.
"Actually, he gave up all claims on his kingdom to avert a clan war as his infamous cousin Devdutta was gearing up for battle."
His film, Ghimire hopes, will also bring into light the character of the prince's wife, Yashodhara, of whom little is known.
"She was a pillar of support to her husband," he says. "They had met before they were married and those scenes bring romance to the film."
It is rather unusual to see an Indian director championing the cause of another country. Ghimire has a vey simple answer to that.
"I just want to present the facts," he says.