An unmanned yacht carrying assault rifles and ammo triggered a brief security scare after it mysteriously washed up on the Indian coast, officials said.

Three AK-47 rifles and an ammunition cache were recovered from the Lady Han after it drifted ashore Thursday in a sparsely populated corner of western Maharashtra state, close to the location of a deadly seaborne terror attack in 2008.

Anti-terrorism investigators seized the UK-flagged boat after it was spotted by fishermen, but authorities established later that day the vessel belonged to an Australian couple who abandoned it at sea after an engine failure on July 26.

British maritime security company Neptune P2P Group claimed ownership of the weapons and said it had been engaged to protect the vessel against pirates during its voyage through the Indian Ocean, Gulf of Aden and Southern Red Sea.

"We would also like to thank the Indian authorities for their investigation and handling of the matter and remain on hand to fully cooperate with them and secure the retrieval of our security equipment," the firm said in a Thursday statement.

The yacht had set off from the United Arab Emirates and was slated to sail into the Mediterranean.

After a storm in rough seas, the entire crew including security staff were forced to abandon the vessel and were rescued by a Korean navy warship which tried and failed to tow the boat, the Neptune P2P statement said.

Maharashtra Deputy Chief Minister Devendra Fadnavis said late Thursday that authorities had for now ruled out "any terror angle" but added that the official probe would continue.

More than 160 people were killed in Mumbai, north of where the Lady Han was found, after a group of militants from neighbouring Pakistan arrived in the city by boat and launched a series of attacks on hotels and other landmarks in 2008.

The incident was one of the deadliest terror attacks in India's history and worsened the perennial diplomatic tensions between the countries.