The divers were found next to the site of the 17th century British warship Coronation, off Penlee Point bordering Plymouth Sound.
The police are awaiting the results of a specialist assessment to determine whether the items raised came from the wreck site.
The interception has come after the February launch of the Alliance to Reduce Crimes Against Heritage (ARCH), which covers sites designated as protected under national legislation.
It has been described by English Heritage as a “voluntary national network” steered by itself, the police and the CPS, and involving bodies ranging from state machinery to local groups.
The aim is for “all the agencies to work much closer together to ensure a fast, appropriate response where there is a suggestion a heritage crime has been committed”.
ARCH covers predominantly terrestrial sites, but maritime heritage sites designated under the Protection of Wrecks Act 1973 fall under the umbrella.
English Heritage has warned that “action will be taken against anyone illegally accessing, damaging or removing items from protected historic wrecks”.
Alison Kentuck, Receiver of Wreck, says: “ARCH is helping to forge closer relationships between a variety of bodies involved in heritage management and those involved with investigating and enforcing heritage-related offences.
“It will hopefully enable more efficient sharing of information, expertise and resources in the future.”
Related links
Coronation official website
Archive | 
Win a Luxfer pony cylinder
