Police suspected it to be a case of illegal immigration.

Six months after a fishing boat carrying more than 100 people set off from the Munambam port in Kerala's rural Ernakulam, a blue corner notice has been issued by the Interpol against the people on the boat. The Kerala Police had requested for the notice to be issued against them around a month ago.

In January, a fishing boat carrying more than hundred people, mostly Tamil migrants from Delhi's Ambedkar Nagar, had set sail from the Kerala coast and went missing. They left behind crucial identification documents and other belongings including bags. Police suspected it to be a case of illegal immigration.

"We have not been able to trace yet the details of where they have gone. This seems to be a case of illegal migration. They probably left in search of better standards of living. Most of the people have left with their families and children, including the organisers themselves. Some of the people known to them had set off on similar journeys earlier," a Kerala police officer told NDTV.

A blue corner notice by the International Criminal Police Organization, more commonly known as Interpol, helps investigators track individuals allegedly involved in criminal cases and suspected to be in other countries.

A team of Kerala police has been camping in Delhi for over two months to probe the case.

Some reports said these people were promised jobs in New Zealand.

"We haven't received any information from the New Zealand government yet. Australian government has been in touch with Indian officials, and have said no one with these details have arrived there either. Some family members shared with us a contact number from Algeria, saying they received one of the 'missing' member's calls from here. But that's hardly a possibility . We have received response from Algeria through diplomatic channels, stating the vessel or people haven't reached there," the police officer further added.