On 8 October 1856, Qing officials boarded the Arrow, a Chinese-owned ship (a lorcha) that had been registered in Hong Kong and was suspected of piracy and smuggling. Twelve Chinese crew members were arrested on suspicion of piracy by the Chinese authorities. The British officials in Guangzhou demanded the release of the sailors, claiming that because the ship had recently been British-registered, it was protected under the Treaty of Nanking. The British insisted that the Arrow had been flying a British ensign and that the Qing soldiers had insulted the flag. As China insisted that it did not hang out the national flag at that time, negotiations eventually broke down, but not before all sailors had been returned to the British with a letter promising great care would be taken that British ships were not boarded improperly. In fact, the registration of the nationality of the Arrow had expired, in which case she did not have the right to fly the ensign, and her crew's arrest by the Qing authorities was lawful.