Cave divers in Mexico's Yucatan peninsula have discovered what may be the world's longest underground river, connecting two cave systems with a waterway at least 95 miles (154 km) long.

A group of foreign divers exploring the area near the Caribbean beach resort of Playa del Carmen have yet to name the stretch, but believe it could be connected to two other major systems, adding more than 125 miles (200 km) to its length.

"It's a bit of the Star Trek syndrome: the thrill of exploration, to go where no one has gone before," said diver Steve Bogaerts, who helped find the underground river.

Prior to the discovery, the Palawan underground river in the Philippines and Vietnam's Son Trach River vied for the record as the world's longest.

The area in southeast Mexico is home to tourist resorts Cancun and Cozumel, as well as Mayan ruins Chichen Itza and Tulum. It sits on a Swiss-cheese subsoil of limestone dotted with deep wells that are entrances to tunnels that have fascinated divers for decades.

The local tourism board said 24,000 visitors went diving in the caves last year.