New Prime Minister Rishi Sunak has been congratulated by his father-in-law, the billionaire IT tycoon Narayana Murthy. 

In a rare public statement, the 76-year-old said: 'We are proud. We are confident he will do his best for the people of the United Kingdom.'

Mr. Murthy has previously been dubbed 'India's Bill Gates' due to his role in pioneering the country's tech boom.

The scion of a middle-class family, he amassed unimaginable wealth after founding tech company Infosys in the early 80s and is now worth an estimated £3.9bn.

His daughter, Akshata Murthy, met Mr. Sunak, also 42, while they were studying at Stanford University in the US. 

The couple shares two daughters, Krishna and Anoushka, and will be the first Hindu family to occupy Number 10. 

Mr. Sunak is the UK's first PM of Asian heritage and the youngest for more than 200 years at the age of 42. 

The news has been welcomed in India, with the country's leader, Narendra Modi, sending his 'warmest congratulations. 

Meanwhile, parliamentarian Raghav Chadha tweeted: 'Today, as India celebrates Diwali in its 75th year as an independent nation, the UK gets an Indian-origin Prime Minister. History comes full circle.'

TV channel NDTV called it 'stunning' while CNBC TV18 described his rise as 'nothing short of a miracle and said Sunak had made the impossible happen. 

It also praised British society for giving Sunak the opportunity to reach the highest office. 

'The greater credit is to Britain itself, for bringing in institutions and developing a culture where Rishi Sunak could be possible,' it said.

Together, the Sunaks have a combined fortune of £730 million, the Sunday Times Rich List revealed in May.     

Ms. Murthy has previously come under public scrutiny for her non-domiciled tax status, which meant she did not have to pay tax on earnings outside the UK. 

It is thought the bulk of her £430m wealth comes from Infosys, which is based in Bangalore.

After the tax revelation was revealed, the couple faced intense backlash – which led to Ms. Murthy ultimately giving up her non-dom status and promising to pay tax in the UK on the fortunes she brought in from around the world.

She released a statement defending her 'entirely legal' arrangement but ultimately decided to give it up. 

The statement read: 'It has become clear that many do not feel it is compatible with my husband's role as Chancellor.

'I understand and appreciate the British sense of fairness and I do not wish my tax status to be a distraction for my husband or to affect my family.'