WASHINGTON (Reuters) - The Supreme Court on Tuesday unanimously upheld the search by a trained police dog of a truck for evidence, saying that training and testing records had established the dog's reliability and given the police probable cause to search.

The case concerned Aldo, a German shepherd whose "free air sniff" helped his police handler find methamphetamine ingredients inside Clayton Harris' pickup truck after it had been pulled over.

The case had been watched closely by criminal defense advocates.

(Reporting by Jonathan Stempel; Editing by Howard Goller and Doina Chiacu)