The whereabouts of a billionaire diamond tycoon on the run from India over accusations of involvement in its biggest banking fraud were known by British authorities months ago, the Telegraph can disclose.

This newspaper tracked down Nirav Modi last week to an £8 million flat he is renting in a tower block in central London, prompting demands by India for him to be sent back for prosecution.

Sajid Javid, the Home Secretary, has now agreed to India’s request for his extradition and the case will now be passed to a judge at Westminster magistrates court to consider the application.

India first asked for the return of Modi in the summer amid reports he had fled to the UK after being accused of embezzling £1.5billion from Punjab National Bank. But sources inside India’s Central bureau of Investigation (CBI) have suggested proceedings stalled because UK authorities were unable to locate Modi.

The tycoon, once one of India’s wealthiest men with a £1.3billion fortune, designed jewellery that was worn by a host of Hollywood stars and owned boutiques including a store in old Bond Street.

The telegraph can now disclose that Modi was given a national Insurance number by the Department for Work and Pensions (DWP) in November.