British Prime Minister David Cameron was due to hold talks with Indian leaders Tuesday in pursuit of deeper trade ties as a widening corruption scandal threatened to overshadow his visit.

Cameron arrived Monday accompanied by the biggest-ever British overseas business delegation in the midst of a political storm over India's purchase of helicopters from Anglo-Italian firm AgustaWestland.

The premier, set for talks with his counterpart Manmohan Singh and President Pranab Mukherjee, is seeking like other Western powers to boost ties with the fast-growing region, and heaped praise on his hosts at the start of the three-day visit, calling India's rise one of the century's "great phenomena".

"Britain wants to be your partner of choice," Cameron told a business audience in Mumbai, the financial hub of the former British colony.

He said the two countries have the foundations for a "special relationship" -- a phrase British leaders traditionally uses to depict its US links.

But the helicopter scandal has taken the gloss off Cameron's second trip to India as he presses for a deeper trade relationship and greater access for British companies in one of the world's most dynamic economies.

After an investigation in Italy suggested kickbacks were paid via middlemen to secure the $748-million (RM2.31 billion) deal, India has taken steps to scrap the contract for the 12 helicopters and started its own police inquiry.

Cameron was expected to face questions from Indian leaders about what Britain knows about inside aspects of the 2010 deal -- with the helicopters being manufactured in southwest England -- as the Indian government, buffeted by a string of graft scandals, is keen to be seen as tough on the latest controversy.

The British leader has targeted a doubling of annual bilateral trade with India, from 11.5 billion pounds (RM 55.23 billion) in 2010 to 23 billion pounds (RM110.47 billion) by the time he faces re-election in 2015.

Among his 100-plus delegation are British executives eyeing moves by the Indian government to open up the retail, airline, banking and insurance sectors to foreign investors.

Amid concerns about a drive to slash immigration numbers and fears that young Indians could be deterred from applying to study in Britain, Cameron stressed in Mumbai that there was no limit on the number of Indians who could study there.

He also announced a new same-day visa service for Indian business people, and said Britain would be "rewriting our rules on the high-level technology that we're prepared to share with our Indian partners".

Cameron was also expected to remind India of the merits of the part-British Eurofighter jet, which was competing for a $12-billion (RM 37.13 billion) contract until last year. India chose France's Dassault Aviation for exclusive negotiations but the deal has still not been signed.