India's coast guards made a massive heroin bust Saturday night when they intercepted a merchant ship off the coast of the western state of Gujarat.

The vessel was carrying 3,300 pounds (1,500 kg) of the white powder worth almost $550 million (470 million euros) when it was seized and taken to the port of Porbandar, officials announced Sunday.

"The ship was intercepted after coast guards received inputs and tip-offs by intelligence agencies. The coast guard says it is the largest single haul of narcotics seized in the country to this date," Defense Ministry spokesman Abhishek Matiman said from the city of Ahmedabad.

The vessel was operating under the name MV Henry and flying a Panama flag as it sailed from Dubai to Alang, a town in Gujarat known for shipbreaking. 

The vessel was carrying eight crew members, all of whom were identified as Indian nationals. They have been detained for questioning.  

Indian law mandates that anyone caught smuggling or possessing narcotics is taken into custody and refused bail.

A lucrative drug route

India lies along a lucrative drug-smuggling route as neighboring Afghanistan is a major producer of opium, the main ingredient in heroin.

But it is still unclear where this heroin originated, and people involved in the smuggling were not immediately known. The Indian coast guard, intelligence agencies, police and the Navy are participating in a joint investigation.

Last year police in the western state of Maharashtra seized 18.5 tons of ephedrine worth $311 million. Ephedrine is used in the manufacture of methamphetamines.

In 2013 police in the holiday resort state of Goa arrested a 45-year-old Briton in possession of more than four kilograms of amphetamines worth $330,000.

Heroin seizures in India have increased in recent years, according to figures from the Narcotics Control Bureau.

Much of the heroin comes from Afghanistan and is smuggled through neighboring Pakistan and into India via the disputed northern state of Kashmir and coastal border areas in the west.

In addition to being on a heroin smuggling route, India has long been a transit route for cocaine and morphine from Afghanistan, Pakistan, Myanmar and Nepal to the rest of the world. 

bik/jm (AP, dpa, AFP, Reuters)