When Castor returned to Britain, the frigate was classed by the Admiralty and the Navy Board as "salvage" rather than as a prize. The laws regarding salvage meant that the proportion of prize money due to be paid to Laforey and his crew was significantly reduced by the declaration. The grounds for this judgement were that after its capture by the French, Castor was not taken into a French harbour and properly condemned by a French prize court and commissioned into the French Navy, the normal legal requirement for what was termed a "complete prize". On behalf of his men Laforey brought a legal challenge against the ruling to the High Court of Admiralty to determine the status of Castor. The judge, Sir James Marriott, heard evidence from a number of parties, including a deposition by Captain L'Huillier that described Admiral Nielly's standing orders to fit out any captured warships at sea for continued service in the campaign. After considering the evidence Marriott ruled that Castor was a legitimate prize "setting forth as a ship of war", and that the normal prize rules should apply to Laforey's case. The prize money for the purchase of the frigate was therefore authorised to be paid at Plymouth on 20 July 1795.
