In the wake of the recent Germanwings crash in the French Alps that killed 150 people, German aviation industry doctors said on Tuesday that pilots should undergo more extensive medical checks.
In response to prosecutors' allegations that co-pilot Andreas Lubitz deliberately crashed the Duesseldorf-bound Germanwings plane on March 24 on a day that he was supposed to be off sick, the head of the German Pilots' Doctors Association urged more thorough examinations.
"We are calling for more frequent and comprehensive laboratory tests for pilots," the association's chief Hans-Werner Teichmueller told Welt newspaper. "We need to see results that can also show traces of psychotropic drugs and narcotics."
In the immediate aftermath of the catastrophe, the association's vice president, Uwe Beiderwellen, had said that he opposed routine psychological tests for pilots.
Germanwings parent company Lufthansa acknowledged last week that Lubitz had informed its flight school in mid-2009, when resuming training after a lengthy medical absence, that he had suffered from a "previous episode of severe depression". He later received the medical certificate confirming he was fit to fly.
German prosecutors said that Lubitz was diagnosed as suicidal "several years ago", before he became a pilot, but doctors had recently found no sign he intended to hurt himself or others. However Lubitz was receiving treatment from neurologists and psychiatrists who had signed him off sick from work a number of times, including the day of the crash.
Ripped up sick notes were found in a flat used by Lubitz, which authorities believe indicates that the 27-year-old was trying to hide his illness from his employer.
A spokeswoman for the Federal Aviation Office (LBA), which issues pilots' licences, said that that Lufthansa had given it "no information about the medical background" of Lubitz.
Lufthansa said in a statement Monday that EU regulations from 2013 requiring more disclosure of medical information on pilots to regulators did "not apply retroactively", that is for the files on Lubitz from 2009.
Citing medical files obtained by investigators, Bild daily reported last week that Lubitz told his doctors he was on anti-depressants and Lorazepam, a mild tranquilizer used to treat anxiety.