New details about the discovery of the San Jose were released on Monday with permission from the agencies involved in the search, including the Colombian government.

"We've been holding this under wraps out of respect for the Colombian government," said Rob Munier, a vice president at Woods Hole Oceanographic Institution.

The exact location of the wreck of the San Jose, often called the "holy grail of shipwrecks," was long considered one of history's enduring maritime mysteries.

The 62-gun, three-masted galleon, went down on June 8, 1708, with 600 people on board as well as a treasure of gold, silver and emeralds during a battle with British ships in the War of Spanish Succession. The treasure is worth as much as $US17 billion by modern standards.

The Massachusetts-based WHOI was invited to join the search because of its recognised expertise in deep water exploration.

The institute's autonomous underwater vehicle, REMUS 6000, helped find the wreckage of Air France 447 in 2011, which crashed in 2009 several hundred miles off the coast of Brazil.

It was REMUS 6000 that in November 2015 took some side sonar images that found the San Jose in more than 600 metres of water.

The vehicle descended to 9 metres above the wreck to take several photographs, including some of the distinctive dolphin engravings on the San Jose's cannons, a key piece of visual evidence.

"It was a pretty strong feeling of gratification to finally find it," said WHOI engineer and expedition leader Mike Purcell, who was not at the site but learned in a phone call from Purcell. "It was a great moment."

The treasure has been the subject of legal battles between several nations as well as private companies. Several weeks ago, UNESCO, the United Nations cultural agency, called on Colombia not to commercially exploit the wreck, whose exact location remains a state secret.

As for the treasure, that remains on the sea bed - for now.

Australian Associated Press