After making his report Stirling went back to patrolling the Caribbean with orders to prevent piracy and the contraband trade. Late in September he seized the . This action turned out to be unwise. The "Hércules", not to be confused with "Hercule" on which Stirling had served in 1804, was nicknamed the "Black Frigate" and had at one time been the flagship of the Argentine Navy. When taken by Stirling, she was a privateer with 22 guns carrying a valuable cargo plundered from Spanish American cities and ships. She was under the command of William Brown, who had been an admiral in the Argentine Navy and was in command of the revolutionary fleet fighting the Spaniards. Her capture compromised the cautious line taken by the British between the Spanish and the revolutionaries. The Governor of Barbados ordered her release, but, when she had left Barbados, Stirling recaptured her and took her to Antigua as a prize. After long drawn-out proceedings, the High Court of the Admiralty ruled in Brown's favour, but he lost the frigate and her cargo. Stirling continued to receive demands for payment of damages for many years.