India has brought charges of culpable homicide not amounting to murder against the chief of a Muslim seminary for holding a gathering last month that authorities say led to a big jump in coronavirus infections, police said on Thursday.

The headquarters of the Tablighi Jamaat group in a cramped corner of Delhi were sealed and thousands of followers, including some from Indonesia, Malaysia and Bangladesh, were taken into quarantine after it emerged they had attended meetings there in mid-March.

Police initially filed a case against Muhammad Saad Kandhalvi, the chief of the centre, for violating a ban on big gatherings but had now invoked the law against culpable homicide, a police spokesman said.

"Delhi police had filed a first information report earlier against the Tablighi chief, now section 304 has been added," the officer said, referring to culpable homicide in the penal code, which carries a maximum punishment of a 10-year prison term.

A spokesman for the Tablighi Jamaat group, Mujeeb-ur Rehman, declined to comment saying they had not confirmed reports about the new charges.

The Tablighi is one of the world's biggest Sunni Muslim proselytising organisations with followers in more than 80 countries, promoting a pure form of Islam.

Authorities said at the beginning of the month that a third of the nearly 3,000 coronavirus cases at that time were either people who attended the Tablighi gathering or those who were later exposed to them.