London: UK Home Secretary Sajid Javid has certified India's extradition request for fugitive diamantaire Nirav Modi, wanted in the Rs 13,500 crore Punjab National Bank (PNB) fraud case, officials involved with the proceedings in the UK confirmed on Saturday, even as he was tracked living openly in a swanky 8-million pound apartment in London's West End and running a new diamond business.

Under the India-UK Extradition Treaty arrangements, the paperwork is now with the District Judge at Westminster Magistrates' Court in London to issue an extradition warrant against Modi to be executed by Scotland Yard.

The Indian authorities were informed of the development on Thursday, with officials here indicating that an arrest warrant against Modi may now be a matter of weeks, moving the extradition request to the next stage.

The confirmation of the certification of the extradition request, filed by the Indian authorities in August last year, came just as 'The Daily Telegraph' reported on Saturday that it had discovered Modi living openly in the heart of London and running a new diamond business just yards away.

Modi, 48, was tracked down to a three-bedroom flat occupying half of a floor of the landmark Centre Point tower block of luxury apartments, where rent is estimated to be around 17,000 pounds a month, the newspaper reported.

The Indian High Commission in London had confirmed in August 2018 that India had handed in the extradition request documents for Modi, which have been under consideration by the UK government since then.

The UK Home Office on Saturday refused to comment on "individual cases" and indicated that any extradition proceedings can go ahead only after an extradition warrant has been issued for the arrest of the accused, as was the case with liquor baron Vijay Mallya.

The 63-year-old former Kingfisher Airlines boss, wanted for fraud and money laundering charges in India, had surrendered to Scotland Yard following such a warrant in April 2017 and is now undergoing an appeal process against his extradition order by Javid, the senior-most Pakistani-origin minister in the UK Cabinet.

The revelation of Modi's whereabouts in London comes a day after his 30,000 sq ft seaside mansion at Kihim beach in Maharashtra was demolished by authorities using explosives.

Despite his bank accounts being frozen by the Indian authorities and an Interpol red notice being issued for his arrest, Modi, a diamond jeweller whose designs have been worn by Hollywood stars, is now reportedly involved in a new diamond business based in London.

In a video posted by the newspaper, a "plumper" Modi can be seen sporting a handle-bar moustache and wearing an Ostrich Hide jacket, estimated to cost 10,000 pounds.

On being accosted by reporters and questioned on various issues, including whether he had applied for political asylum in Britain and what he had to say after the charges against him, Modi responded to a volley of queries with a curt: "No comment".

According to the report, the fugitive businessman has been given a National Insurance number by the UK's Department for Work and Pensions (DWP) in order to be able to legally work in Britain and has also been able to operate online bank accounts in the country.

Modi is the subject of an Interpol red notice since July last year, which is a request to locate and arrest a wanted individual pending extradition proceedings.

However, if Modi has applied for political asylum in the UK, that process may hamper any arrest until his asylum application is considered by the UK Home Office.

"It is much harder to succeed in an asylum claim from a constitutional democracy like India. However, if there was evidence of an unfair trial, a person's claim might succeed," said Mark Symes, a senior immigration barrister who has represented another wealthy Indian national in the past who was refused asylum by the UK Home Office but won the claim before an independent judge on appeal.

"Generally speaking, a person needs to prove they face persecution rather than prosecution. So, a legitimate prosecution that leads to a lawful conviction following a fair trial could not give rise to a viable claim. However, if the charges were politically motivated or the trial was very unfair or excess punishment might result, the claim might succeed," he said.

Modi is believed to have arrived in London last year and was able to travel in and out of Britain at least four times since his passport was cancelled by the Indian authorities in February 2018.

During some of his stays in London he was reportedly also living in the heart of the city above his jewellery boutique called "Nirav Modi" on Old Bond Street, which has since closed down.

Modi is now believed to be running a new business which describes itself on the UK's Companies House register as a wholesale trader in watches and jewellery and a retailer of watches and jewellery in specialised stores.

While Modi is not listed as a named director of this new business, the UK media report claims he was seen walking his dog from his flat to the new office.

Modi and his uncle, Mehul Choksi, are the main accused in Punjab National Bank (PNB) scam and they both left India before the details of the fraud came to light in January 2018.