The decision ends a long-running dispute over environmental data sought by campaigners regarding the Port Navas Oyster Farm near Falmouth. The campaigners were concerned about the cultivation of non-native oysters in the area, which is an officially designated conservation zone.
An initial ruling by the Information Commissioner in October 2010 that the Duchy was not a public body subject to the disclosure regulations was overturned by a First-Tier Tribunal in November 2011.
The Principal Judge, John Angel, ruled that, “In a modern day context, the Duchy is carrying out the public function or service of providing an income for the undertaking of an extremely important constitutional role in the UK."
He concluded: "The Duchy is also a public authority in performing its primary function and the provision of an income for the Duke is a function of public administration".
This ruling threatened to leave the Duchy open to further information requests but Mr Justice Charles, President of the Upper Tribunal's Administrative Appeals Chamber, ruled the estate was "not a public authority" under environmental information rules and therefore has "no obligation" to provide information.
The Duchy of Cornwall owns most of the freehold land on the Isles of Scilly. They are also the Competent Harbour Authority, granted statutory powers relating to the provision of pilotage services, and the Local Lighthouse Authority devolved under Trinity House to provide navigational aids.
In April last year, the Duchy submitted a formal proposal to the Marine Management Organisation to change the status of St Mary’s harbour to a Trust Port.
Some local residents held a view that this decision was made as a precaution against the Duchy losing their information disclosure appeal so it remains to be seen if this overruling has any bearing on the long-term running of St Mary’s harbour.