Stockholm (AFP) - Swedish wreck divers said Monday they had found the wreck of a Russian mini-submarine in Swedish territorial waters, nine months after a high-profile hunt in Sweden for a mystery submarine.

The Swedish military reacted with caution to the claim.

"It is they who claim it's a submarine," Swedish Armed Forces spokesman Anders Kallin told AFP.

"Our analysts have not yet presented their conclusions and want to see more images which the (diving) company will send to us," he said, adding that the results were expected "in the coming days". Kallin said the military would "not speculate".

According to Stefan Hogeborn, a diver from the Ocean X Team company that made the discovery, the vessel is "completely intact" with "no visible damage to the hull" and the hatches closed.

"It is unclear how old the submarine is and how long it has been laying at the sea floor, but the Cyrillic letters on the hull indicate that it is Russian," he said in a statement.

Hogeborn did not given the vessel's location but according to Expressen tabloid, which published images of the wreck on its website, it was found about 1.5 nautical miles (2.8 kilometres) off the east coast of central Sweden.

Ocean X Team said the vessel was around 20 metres (66 feet) long and 3.5 metres wide.

In October last year, Sweden's navy launched a massive hunt for a foreign submarine, suspected to be Russian, in the Stockholm archipelago.

The military subsequently confirmed that "a mini-submarine" had violated its territorial waters, but was never able to establish the vessel's nationality.

"We don't believe there is a link with last year's submarine hunt," a member of the Ocean X Team, Peter Linberg, told Expressen, without elaborating further.

Ocean X Team said it was planning a new expedition to examine the wreck more closely.