A team of maritime archaeologists, scientists and surveyors has discovered what it believes to be the world's oldest intact shipwreck — a Greek trading vessel whose design had previously been seen only on ancient pottery.

The Black Sea Maritime Archaeology project says it found the wreck off the Bulgarian coast at a depth of two kilometres (1.2 miles) in oxygen-free conditions that preserved its components. The group says the vessel has been carbon dated to more than 2,400 years ago.

The project has spent three years surveying the area using technology previously available largely to oil companies. It discovered some 60 shipwrecks, including a 17th century Cossack raiding fleet and Roman trading vessels carrying amphorae.

The design of the Greek trading vessel had previously been seen only on ancient pottery. (Black Sea Maritime Archaeology Project)

A documentary on the project will open Tuesday at the British Museum.