Divers say a 3,000-year-old Devon wreck site has been deliberately sabotaged.
A gold torc was among the finds
The site, about 18m underwater off Prawle Point, has revealed Bronze-Age artefacts including axe heads, rapier blades and a gold torc.
The South West Maritime Archaeology Group (SWMAG) have discovered marker buoys deliberately cut and seabed markers ripped up around the wreck.
English Heritage has been informed and is investigating the incident along with coastguards.
Mike Palmer of SWMAG found the damage when he was diving at the site, which is under restricted access to licence holders only by English Heritage.
He told BBC News: "The rope on the buoys had been deliberately cut, and the buoys discarded.
"The seabed markers have all been cut.
"It's a huge setback because we have spent the last eight weeks laying them."
The lines and buoys cost about £5,000.
He said coastguards and local people had been asked to keep a watch on the site.
The hoard was found two years ago as the team of divers explored the site of a 17th century wreck half a mile off Salcombe.
Experts believe some of the objects are from northern France and the swords are among the earliest found in north-west Europe.