Last week they were declared Britain's wealthiest Asians by the newspaper Eastern Eye and are among the nation's 10 richest people. Yet, every time they try and put something back into the country where they have been based for the past 20 years, they whip up a media furore. The tragic Romeo- and-Juliet style death of one of their sons, and the still-unproved allegations that they have been involved with a Swedish arms maker, which resurfaced in the press again last week, add intrigue to the mixture.
Srichand (SP for short), Gopichand, (GP), Prakash and Ashok - known affectionately in India as the Fab Four - run an industrial conglomerate comparable with the former empire of Lord Hanson. Their personal fortune is worth an estimated pounds 1.3bn in interests ranging from oil and banking to films and fork-lift trucks.
If other business magnates of comparable wealth, such as Lord Sainsbury or Richard Branson, appear in public with political leaders, no one bats an eyelid. That, after all is expected of industrialists. But when it's the Hindujas - who count among their friends personalities as diverse as Edward Heath and Rosie Boycott, editor of The Express - they are immediately accused of ulterior motives. When they stepped in last year to contribute pounds 3m to the controversial religious part of the Millennium Dome, the Spirit Zone, suspicion was immediately raised they wanted to turn us all into Hindus.
SP, who at 63 is the oldest brother and family patriarch, sounded more like an endearing Indian theologian than a tycoon when he called me from Bombay on Friday. He was more prone to talk about the nature of prophets than profits.
For a family who give millions of pounds away to charity every year through their Foundation, the contribution to the Millennium Dome was not a lot of money. Other beneficiaries of their charitable vocation in this country include the Victoria and Albert museum, the Prince's Youth Business Trust and a magnificent Hindu temple in North London.
For SP, the Spirit Zone was exactly the right opportunity to promote the family's vowed intent to crusade for better multi-cultural understanding here and abroad. It backfired amid concern that the celebration of Jesus Christ's 2,000th birthday was being hijacked by non-believers.
"My family name, Hinduja, is misleading," SP told me. "They [critics] thought I wanted to convert the Christians to Hindus. Our faith is that we all belong to the human race."
The Hinduja Group is a tight family ship running a global empire with a worldwide staff of 25,000. Its flagship company is Ashok Leyland, the Indian maker of commercial vehicles currently being courted by a number of car companies wishing to break in to that growing market in India. It owns India's biggest importer of petroleum, Gulf Oil International. It has a bank in Switzerland, Amas Bank, the first Indian-owned private bank in Europe. There is also a pharmaceuticals company and a pounds 1.4bn joint venture power project with the UK's National Power. Other Hinduja businesses include a cargo venture with the German airline Lufthansa.
SP and GP, who's 58, head the company's British-based operation from New Zealand House in Haymarket, London. Ashok, 48, looks after their business interests in Bombay and Prakash, 53, is based in Geneva. So close and orthodox are the brothers that they married three of their sons on the same day, inviting 6,000 guests into the bargain, many of them flown from London in private planes.
"We focus always on our family. There are our brothers and four sons in the business" explains SP. "We try to see who has which expertise in each sector and try and develop every individual for that so he can bring the maximum economic strength."
The benefits of this system are clear for SP. "In the professional world, there is always a lot of politics. We say: `Let's follow this philosophy which will give all of us the maximum growth and be better for our health because we will not waste our time becoming upset."
Internecine power struggles are also avoided by strict adherence to a rigid patriarchal structure and their Vedic religion, which also forbids them from doing business in meat, alcohol or tobacco.
It is a formula soured only by the death of SP's youngest son, Dharam, six years ago. Dharam had married a Roman Catholic, Juliet Ninotchka, against the family's wishes and eloped with her to Mauritius. When the family found out, the pair tried to kill themselves by dousing themselves with petrol and setting themselves alight. Ninotchka survived but Dharam died. The inquest ruled the death was suicide, but SP to this day refuses to acknowledge his son committed suicide.
The Hindujas' fortune was started by their father Parmanand, who comes from the province of Sindh, now a part of Pakistan, centrally placed on the trade routes between East and West. Parmanand started trading from the age of 14, importing carpets, dried fruits and saffron from Iran and exporting textiles, tea and other spices in the other direction. Iran soon became the Hinduja's business base.
SP entered the family business, worth several million pounds even then, at 19. By that time, his father was also making money out of selling films. He was the first person to market internationally the films of Bollywood, as the Bombay film industry is called, which are now vastly popular across the developing world. The family's London holding company, Sangam, is named after a popular Bollywood film.
There have been rumours that the Shah of Iran was so impressed with Parmanand that he left him a large sum of money, although that has never been proven. Some have accused the brothers of acting as go-betweens in the arms trade between Iran and the West, but no concrete evidence has ever surfaced.
They are certainly not naive when it comes to the importance of getting on with the right people. Indeed, the family managed to continue to operate in Iran after the Shah was deposed by the Ayatollah Khomeini. The ability to ingratiate themselves with the powers that be led to claims that the Hindujas donated pounds 6m to the Conservative Party during Margaret Thatcher's administration.
SP vehemently denies this. "There is a lot of confusion about funds for the Conservative Party. We have given money to all the parties in all the periods if they are supporting a good cause. We consider this is our duty." He refuses to be drawn over whether he has given any cash to Tony Blair.
More recently, the Hindujas have been expanding into the world of telecommunications and media. I ask SP to tell me more about that and he refers me to "one of our sons", Remi, in Geneva. The Hindujas make little distinction between sons and nephews. "He is a man with a lot of vision on the subject. You will be overwhelmed once you have spoken to him," says SP. I give Remi a call. He certainly sounds impressive. In a distinct American accent, he explains how the family has built the largest cable television network in India, with 3 million subscribers. It also runs the country's most popular music channel, has joint ventures in satellite television and is preparing to launch a digital platform in that country. The family is also exploring ways to deliver internet services via its cable network. The Hindujas have one of the fastest growing software companies, based in the India's hi-tech capital, Bangalore. A global television channel is also on the cards.
But multi-culturalism is the main focus of SP's passions. People who know him say that his interest in the issue has increased since his son's death. SP has even commissioned a movie script writer about the subject and plans to have a film made in Hollywood.
So far no deal has been clinched. The storyline dreamt up by SP is designed to promote inter-cultural understanding, possibly too soft a subject for Hollywood. The Hindujas' own story would make a better plot for Tinseltown.