After leaving port in March disguised as the Norwegian freighter Rena Norge, the Leopard set sail its mission to disrupt Allied commerce. On the 17 March it was stopped in the North Sea by the cruiser HMS Achilles and ordered to proceed to the boarding vessel HMS Dundee for inspection Heavily outgunned Captain the raider's commander Hans von Laffert had no option other to proceed to meet the boarding vessel. Captain Selwyn Day of the Dundee dispatched a launch containing a boarding party with an officer and five men to investigate the mysterious ship. Hans von Laffert realizing he was about to be discovered detained the party and after about an hour opened fire on the Dundee with a salvo of two torpedoes. The steamer manoeuvred out of the way barely in time and the torpedoes missed Captain Day's ship by twenty feet. Day ordered his guncrews to open fire and a hail of shells struck the Leopard damaging a gun and setting fires. The Achilles hearing the sound of gunfire returned to the scene and opened fire on the raider as the Dundee withdrew. Shortly after the Achilles's arrival the Leopard sank with all 319 hands going down with the ship. Damage to the British vessels was light and the only casualties consisted of the six boarding party members who were trapped in the Leopard when it sank.