A ship carrying 1,700 tonnes of whale meat left Iceland on Thursday bound for Japan, said a leading animal welfare group that is protesting against the controversial delivery.

The website Marinetraffic.com also showed the vessel, known as Winter Bay, leaving Hafnarfjordur port in western Iceland just after 1030 GMT.

"Winter Bay has left Hafnarfjordur harbour with 1,700 tons of whale meat with Ghana... as their first destination," Sigursteinn Masson, Iceland spokesman for the International Fund for Animal Welfare, told AFP.

Iceland and Norway are the only nations that openly defy the International Whaling Commission's 1986 ban on hunting whales.

Japan has used a legal loophole in the ban that allows it to continue hunting the animals in order to gather scientific data -- but it has never made a secret of the fact that the whale meat from these hunts often ends up on dining tables.

The Winter Bay had been due to leave Iceland in mid-May but was delayed due to mechanical problems.

"My source tells me they need to stop at least four times on the way to Japan which could be very difficult" due to possible protests, Masson said.

Last year, a shipment from Iceland to Japan made only one stop outside Madagascar's harbour. A stop had been planned in South Africa but was cancelled after protests prompted the government to declare them unwelcome, he added.

When Winter Bay was delayed in May, Masson told AFP that the shipment of whale meat was an issue of animal welfare.

"There is no humane way to kill animals of that size... There is no need for this meat and certainly no need for Iceland's economy or fisheries industry to have this," he said.

"This is a shipment that faces strong international opposition... Commercial whaling is a very isolated business -- we want to see the end of it, as does most of the world."

Icelandic whaling company Hvalur HF is sending the shipment.

Icelandic whalers caught 137 fin whales and 24 minkes in 2014, according to the Whale and Dolphin Conservation group, compared to 134 fin whales and 35 minkes in 2013.

Consumption of whale meat in Japan has fallen sharply in recent years while polls indicate that few Icelanders regularly eat the meat.