ALIEN spaceships under the sea might sound like the stuff of fiction, but a UFO researcher claims that an incident off the shores of Anglesey could be the best evidence yet of an infamous North Wales close encounter.

However, UFO expert Russ Kellett said that a coastguard document backed his theory that one of three alien craft found off the coast of Anglesey crashed into Lake Bala and caused the Berwyn Mountain incident January 23 1974.

He said: “This information that I have unleashed is a sort of Holy Grail. The Ministry of Defence released documents a year ago and there was nothing about military activity.”

The researcher, who has investigated the UFOs for 23 years, said that the Marine Coastguard document revealed that a military exercise called Operation Photoflash was underway from Liverpool Bay to the North Wales coast on the night of the Berwyn Incident.

Russ believes that the operation used depth charges to locate one alien craft at Puffin Island, another off the Anglesey coast and a further ship near Bangor.

The spaceships then shot out of the sea and into the air.

Russ said that a group of men discovered one of the silver flying saucers while the aliens emerged from one of the crashed ships on a roadside near Llandrillo.

He said: “They were slim humanoid creatures, about five ft six inches tall, with grey skin and wore jumpsuits with belt kits on them.”

Russ added that the men watched the soliders load the aliens into a vehicle and drive away.

The researched believed that the MoD had not released the information to prevent public panic.

He said: “You’ve got something that travels about under the sea without detection and can fly. What a piece of engineering that is.

“People are going to get really worried, because this is what I call super technology.”

Russ also claims to have several fragments of one of the craft.

Documents released by the MoD last year support the theory that a meteor shower caused the bright lights and earthqauke experienced by residents near the Berwyn Incident’s epicentre at Bala Lake.