Unfortunately the story about Rex Cowen is largely just a malicious rumour, the deal with the Dutch government was agreed many years before the wreck was found and did not change. There were representatives of the Rijks museum on board during the location and excavation of the only coin chest found. Other lose coin was also found under supervision from the museum. There is disputed stories of Cowens contractor illeagally exporting some Ducatoons.
Various searches have been made for the Anna Catherina but it appears to have been heavily trawled by trawlers, is in a very tidal location and is difficult to search due to the proximity to shipping lanes.
As far as I know there is nothing stopping the location and excavation but I believe Mr Cowen had or has a contract in place for this wreck as well.
in 2005/6 a similar recovery with a Dutch government/Cowen split of finds was made for the wreck of the Rooswijk.
Wikipedia:
"Lying at a depth of about 24 m, the Rooswijk was discovered on the Goodwin Sands by an amateur diver in 2004. It lies in about 24 metres (79 ft) of water at the northeast end of Kellett Gut.
In December 2005, it was made public that between May and September of that year a team led by Rex Cowan had recovered some of the ship and its contents. This was done in secrecy to avoid attracting looters. Artifacts recovered included approximately one thousand bars of silver, gold coins and a mustard jar. When the VOC was disbanded in 1798, its possessions fell to the Batavian Republic, the legal successor of which is the current Dutch State, which therefore is entitled to the objects from the Rooswijk. They were presented to Junior Minister of Finance Joop Wijn in Plymouth on 11 December 2005.
The type of coins recovered were several hundred Mexican silver cobs of the 1720s and early 1730s and transitional "klippes" of 1733-1734, as well as many more hundreds of “pillar dollars” and a smattering of cobs from other mints.
The salvage operation has led to criticism from heritage organisations worldwide, as some of the international principles concerning the protection of archaeological heritage (Valetta Treaty 1992, UNESCO Convention on the Protection of the Underwater Cultural Heritage 2001) were ignored.
The wreck site was designated as a protected wreck on 18 January 2007. Statutory Instrument 2007/61.
