Mumbai: All cargo on the Wan Hai 503 container ship, which caught fire off India's west coast on Monday, was properly declared, with the cause of the blaze still under investigation. This information was disclosed by a source involved in the probe to CNA on Tuesday.

According to Focus Taiwan, customs documentation had been filed in every country the vessel passed through. This statement comes amid speculation that the ship, operated by Taiwan-based Wan Hai Lines, might have been carrying illegal cargo. The fire broke out while the ship was on a joint service route involving multiple shipping companies and containers, making it challenging to pinpoint the exact origin of the blaze and the container responsible.

Earlier reports by Indian media outlet ETV Bharat indicated that the ship carried hazardous cargo, including flammable solids and liquids, as well as toxic substances. A senior officer at Azhikkal Port was quoted saying the ship's containers held dangerous cargo, including Class 3 (flammable liquids), Class 4.1 (flammable solids), Class 4.2 (spontaneously combustible substances), and Class 4.6 (toxic substances).

The Wan Hai 503 had departed from Kaohsiung in late May, with scheduled stops in Hong Kong, China, Singapore, and Sri Lanka before heading toward Mumbai. The fire erupted while the vessel was sailing off the coast of southern India near Beypore Port, after leaving Colombo on Saturday evening.

The Taipei Economic and Cultural Center in India reported that 18 of the 22 crew members onboard were rescued after abandoning the ship. However, four crew members remain missing, including two Taiwanese, one Indonesian, and one Myanmar national. Among the rescued, five sustained injuries: two Chinese crew members suffered burns; one Myanmar national experienced facial burns; another from Myanmar had general burn injuries; and an Indonesian crew member, although seriously burned, remains conscious.