Over a year ago, when Kabul resident Mehboobullah Khan came to India to work with All India Radio, he could not have imagined that his sojourn would result in a book on Bollywood - tracing how Afghan-origin actors and filmmakers contributed to make it the world's most prolific film industry.

Mehboobullah's countrymen and women are voracious consumers of Indian films and television serials, with the half-dozen movie halls in the Afghan capital continuously running only Bollywood movies.

"When I was there, I noticed that there are so many Khans in the Indian film industry. So, it gave me an idea to do some research, " Mehboobullah told a visiting correspondent. The 28-year-old journalist had gone to India to work with AIR's external services division, which also broadcasts in Dari and Pashto.

His aim was to show how transplanted Afghans have settled and helped to grow Bollywood to its present status. "I wanted to write about how the Pathan community has excelled in the Indian film industry, " said Mehboobullah.

For five-six months, he did research by reading as many books as he could get his hands on, after his working hours in Delhi. "But then I felt that I needed to do some field work, " he said.

So, he went traipsing to Mumbai, hoping to make personal contact with the superstar Khans. "It was very difficult to get to meet them... unless you know somebody, " said Mehboobullah.

He finally got access through a roundabout way - and used a highly-placed contact in the Afghan government, who knew a close associate of Indian superstar Salman Khan. "I went for three days to Salman Khan's residence to interview him, " he said.

He even went to Pune to watch Salman shooting for a forthcoming movie, "Bodyguard", also starting Kareena Kapoor. He also interviewed the rest of Salman's clan, including his brother Arbaaz and father Salim.

Salim Khan's father was from Afghanistan, who had settled in Madhya Pradesh.

After that, doors started opening for him in Bollywood - and Mehboobullah met with the other Khans, directors Sanjay Khan and Farah Khan and veteran actor Kader Khan.

"Sanjay's Khan brother, Feroze Khan had gone to Afghanistan to shoot his film, 'Dharmatma'. He told me that he had wanted to go back, but the situation was not inimical for the visit, " he said.

Their father came from Ghazni in Afghanistan, and settled in Bangalore where the Khan brothers were born. Feroze Khan went to Afghanistan to make his 1975 film, which was the first Indian movie to be shot in the starkly-landscaped country.

Only two other Indian films have also been shot in Afghanistan, "Khuda Gawah" (1992) and "Kabul Express" (2006).

Then, he also met with 75-year-old Kader Khan, who is a popular character actor and comedian in over 300 films. "He spoke to me in Pashto, talked about Afghanistan... and he spoke about his family coming from Kandahar, " said Mehboobullah.

Farah Khan, whose family originally is a Pathan from Peshawar, promised to help in promoting his book in India, once it is published. "She has told me that she will do a fashion show in Mumbai, " Mehboobullah narrated to IANS.

However, despite persistent efforts, he has still not been able to meet either of the two other reigning Khans - Aamir and Shah Rukh. While Aamir's family hails from Herat, Shah Rukh Khan's paternal grandfather was from the region. "I will continue to try to meet them again, " he said.

Now back in Afghanistan, his book on the Khans in Bollywood was published in his country's two official languages, Dari and Pashto, in April. "I hope to be in India next month to look at printing an English version of my book there, " said Mehboobullah.