The 48-year-old diamond magnate, who denies the charges, faces the possibility of extradition to India where Prime Minister Narendra Modi is under pressure to take a firm stance on the case ahead of national elections in April-May.
“I find that there are substantial grounds to fear failure to surrender," magistrate Emma Arbuthnot said in a Westminster court, adding that the fact Nirav Modi had in 2017 applied for a visa to the Pacific island nation of Vanuatu exacerbated those concerns.
A witness has alleged that Nirav Modi threatened to kill him and also offered around ₹20 lakh ($28,918.45) as a bribe not to testify, Toby Cadman, a lawyer representing the Indian government, told the court.
The prosecution also alleges that mobile phones and a server containing evidence critical to the PNB fraud case have been destroyed at the request of Nirav Modi, said Cadman.
Clare Montgomery, a lawyer representing Nirav Modi, said there was no evidence to support the claims of witness intimidation.
Nirav Modi, whose diamonds have adorned Hollywood stars such as Kate Winslet and Dakota Johnson, is among those accused of defrauding Punjab National Bank in a case that has shaken confidence in a state banking sector which accounts for some 70% of India’s banking assets.
The diamond magnate was arrested in the Holborn area of central London last week after he went into a bank to open an account and a member of the staff contacted police.
Nirav Modi will next appear before the court via a video link on 26 April.
Earlier, the Crown Prosecution Service, arguing on behalf of Indian authorities, said Nirav Modi should not be granted bail because he posed a significant flight risk and had even issued death threats to witnesses related to his fraud and money laundering case.
“Given the nature and seriousness of charges and the resources available to him…there will be an overwhelming desire to flee the jurisdiction and interfere with the administration of justice," said Cadman.
PTI contributed to this story.