An anti-tank rocket launcher has been handed in at a Cornish police station - as part of a national knife amnesty. The American-made M72 weapon was so big it could not fit into the amnesty wheelie bins at Wadebridge police station in north Cornwall. A Devon and Cornwall Police spokesman said the weapon was handed in at the end of April. "We will take other weapons, although this was a surprise," a spokesman said. "But this is not the first rocket launcher we have had. "In 2003, during the gun amnesty, a 66mm anti-tank launcher was also brought in." It is not known if the weapon can be used as no-one has tested it, but it will be destroyed along with the host of other weapons handed in. The M72 is about 700mm long and was designed by the US as a single-shot disposable rocket launcher to give infantrymen a lightweight weapon to operate against tanks.