The London-based Srichand and Gopichand Hinduja, who have a fortune of 11.9 billion pounds - "up by an astonishing 1.3 billion pounds in the past year", edged out steel tycoon Lakshmi N Mittal and Russian magnate Alisher Usmanov, according to the 'Sunday Times Super-Rich List' made public today.
The Hinduja brothers, who run the multinational Hinduja Group conglomerate with interests across automotive, real estate and oil, moved up from third position last year to top the UK's billionaire charts this year.
The list - a full version of which will be released next Sunday - also includes NRI industrialists such as Lakshmi Mittal and family, Prakash Lohia, Lord Swraj Paul and family, Anil Agarwal and Ajay Kalsi and family among the city's 72 billionaires.
Mittal also edged one position upwards to the third rank with 10.25 billion pounds even as Russian magnate Alisher Usmanov, who topped the list till last year, fell to the second place.
"Last year, the Hindujas sold a 49 per cent stake in a Saudi Arabian lubricants maker, Petromin, for more than 200 million pounds. Property investments in India have added 200 million pounds.
The family's IndusInd bank is capitalised at about 2.7 billion pounds. In Britain, Hinduja Automotive turned over about 1.5 billion pounds in 2012-13," the newspaper said.
In reference to the Kolkata-based Mittal, the newspaper highlighted a final bounce in fortunes after a few years of dip. "After a tough few years in the steel industry, Mittal is seeing a glimmer of light.
Arcelor Mittal shares have recovered, making his stake worth 6.65 billion pounds - up 700 million pounds in a year," it said. Mittal's brother-in-law India-born textiles and plastics tycoon Lohia is ranked as Britain's 46th richest man with around 2.11 billion pounds.
Leading NRI industrialist and Caparo chief Lord Swraj Paul is ranked Britain's 48th richest, with an estimated wealth worth around 2 billion pounds.
"The 83-year-old came to Britain from India in 1966 to seek treatment for his daughter's leukaemia. He stayed after her death and founded steel manufacturer Caparo, which made more than 62 million pounds profit in 2013. The company has been restructured, with its American and Indian businesses worth 1.6 billion pounds," the newspaper said.
"Paul is chancellor of Westminster and Wolverhampton universities. In memory of his daughter he set up the Ambika Paul Foundation, which supports children's charities," the newspaper said.
Vedanta Resources chief Agarwal at 50th rank and Indus Gas supremo Kalsi at 102nd complete the Indian presence among the London-based billionaires.
"More than half, 39, of London's 72 billionaires were born abroad, but nationally the proportion was lower, with 44 of the 104 across the country born outside the UK," the Times said in its overall analysis.
This year's list also found that London has more billionaires than any other city in the world and the number of billionaires living in the UK as a whole has risen to more than 100 for the first time.
There are now 104 billionaires based in the UK with a combined wealth of more than 301 billion pounds. The British capital is home to 72 people whose aggregated family wealth tops 1 billion pounds.
The next most prosperous world city is Moscow, which boasts 48 billionaires, just ahead of US cities New York and San Francisco.
"London is the financial centre of the world. It straddles time zones so they can come here and get the best financial advice. They like the culture, the tax regime is very nice for them and they feel safe here," said 'Rich List' author Philip Beresford, explaining London's supremacy.
For the first time this year, the world's super-rich needed a net worth of 1 billion pounds to make it to the Rich List's top 100 and a fortune of 1.7 billion pounds is now required to make the top 50 up from 700 million pounds 10 years ago.
The Duke of Westminster is the richest Briton with around 8.5 billion pounds and is ranked 10th on the list.
Other notable figures in the top 25 include Chelsea Football Club owner Roman Abramovich (8.52 billion pounds), Sports Direct owner Mike Ashley (3.75 billion pounds) and Virgin Group founder Sir Richard Branson (3.6 billion pounds).