The crash triggered a scare that the waters of Lake Constance had been polluted by spilt nuclear material, and prompted a manhunt for the pilot and his four passengers, who are now thought by police to have engineered the crash.
The Swiss authorities have recovered the plane from the bottom of the lake, but despite an extensive search involving underwater cameras, they have yet to find any incriminating evidence.
Swiss papers have been full of rumors that the German-registered plane was smuggling radioactive material when it crashed on 24 January, and some 300 journalists and 4,000 people were on hand yesterday to see it winched to the surface. Most troubling for the authorities however, is the whereabouts of the five people and one dog, a terrier called Asta, who were on board.
The Cessna aircraft was flown by an experienced pilot, Rudolf Wirchen, and among his four passengers were two shady businessmen from Berlin, known to Interpol as smugglers of arms, pornography and rare metals. Two Czech female passengers who were on the plane are also missing, although their suitcases have been found by the police.
The alarm about possible radioactive contamination began when the Swiss police revealed that the two men - Josef Rimmele, 54, and Klaus Eichler, 53 - were on Interpol's files for having previously smuggled Caesium 133, a non- radioactive substance. According to the International Atomic Energy Agency in Vienna, this was confused with Caesium 137 which is highly radioactive, setting off a media meltdown in Switzerland and parts of Germany.
Yesterday, as the wreckage of the rented twin-engined Cessna was brought to the surface, suspicions grew that the plane had been deliberately ditched and that its passengers had fled, possibly after being picked up by a boat. According to the police, the aircraft door had been unlocked from inside and all the seatbelts were unfastened when the plane was raised.
A Swiss government aircraft expert, Klaus Gallmeister, said that the plane had made a 'textbook landing', with its wheels retracted, compounding the suspicion that all those aboard left the plane before it sank.
Despite the hysteria which the crash has caused around Lake Constance - from which some 30,000 people obtain their drinking water - no radioactive contamination was found in the lake and the authorities have dismissed the fears.