Prosecutors on Wednesday sought six years in prison for a man charged with theft even though police gathered evidence against him using global positioning data without a warrant, a practice that was ruled illegal by Japan's top court last month.
Yasunari Fukuma, 48, is suspected of stealing vehicles in eastern and western Japan between August 2013 and June 2014. He also faces charges including drug use and possession.
The defense called on the Tokyo District Court to disregard evidence from the GPS investigations, while prosecutors claimed that the legal breach was "not significant" as the GPS use was essential in the investigation and did not greatly interfere with the defendant's privacy.
The court is scheduled to hand down its ruling on May 30.
The trial follows the Supreme Court's March 15 ruling that the collection of GPS data violates privacy and therefore requires a warrant.
The court also said legislation is needed to allow GPS use in investigations, since the current warrant system does not cover such techniques.
Following the ruling, the National Police Agency ordered all prefectural police forces to refrain from GPS use in investigations.