Australian police have issued a warning over a potentially deadly drug that is 10,000 times as strong as morphine.Carfentanyl, a toxic synthetic opioid, is commonly used to tranquilise large animals such as elephants. Queenslnd Police said the drug was intercepted in a mail centre. It was first found in Australia last year. The US Drug Enforcement Agency warned in September that carfentanyl had been linked to a “significant number” of overdose deaths in the US. Queensland Police Minister Mark Ryan said a 0.002mg dose was enough to cause death. “Make no mistake, these are not party drugs,” Queensland Police Supt Jon Wacker said on Friday. “These are dangerous drugs and it’s not a matter of if it will kill you. This drug will kill you.” Carfentanyl was not a controlled substance in China until this week. Beijing on Thursday regulated carfentanyl and three similar drugs after lobbying from the US. In October, the Associated Press said it identified 12 Chinese companies willing to export carfentanyl for as little as $2,750 (£2,200) per kilogram. Queensland authorities feared more of the drug may have entered Australia after the discovery in Brisbane. Even touching carfentanyl posed a danger, Supt Wacker said. “It is unclear how it would be marketed here, whether sold in its pure form or mixed with other drugs and sold as the latest ‘hook’,” he said.