A research team led by Microsoft co-founder and philanthropist Paul Allen has released the first underwater footage of what they say is the wreck of a massive Japanese World War II battleship that sunk off the Philippines more than 70 years ago.

The US billionaire announced his private exploration team had found the Musashi, one of the largest warships ever built, lying at the bottom of the Sibuyan Sea at more than 1km (3,280ft) of depth earlier this week.

Allen, 62, tweeted photos of the wreckage and details of the discovery from his personal account.

He said the vessel, which was commissioned in 1942 and sank by US warplanes in October 1944 during the battle of Leyte, was found on Sunday (1 March) by the research team aboard his superyacht M/Y Octopus, using an autonomous underwater vehicle.

Later a clip showing parts of the wreckage, including a valve wheel, a catapult system used to launch planes, a gun turret and one of the anchors, was posted on Allen's personal website.

"Mr Allen has been searching for the Musashi for more than eight years, and its discovery will not only help fill in the narrative of WWII's pacific theatre, but bring closure to the families of those lost," an accompanying statement read.

"Musashi weighs 73,000 tons fully loaded, and was armed with nine 45 Caliber Type 94 main guns. Roughly half of the crew members were killed when the ship sank."

Allen, whose net worth of $17.5bn (£11.4bn) makes him the 51st richest person in the world according to Forbes, said his fascination for WWII history has been inspired by father's service in the conflict.