The deputy parliamentary leader of the conservative Christian Democrats (CDU), Andreas Schockenhoff, told the Frankfurter Rundschau that the Bundestag's inquiry, which has focussed on political statements made by Defence Minister Karl-Theodor zu Guttenberg, should end.
In September last year, an air strike ordered by Colonel Klein on two petrol tankers hijacked by the Taliban killed an estimated 142 people in Afghanistan, among them dozens of civilians.
“The point of the investigation has been argued to exhaustion,” said Schockenhoff, adding that legally, Klein had “nothing to answer for.”
On Monday, the Karlsruhe-based prosecutors' office announced Colonel Klein had broken neither German nor international law because he had every reason to assume only insurgents were around the hijacked tankers, not civilians. The announcement ended a long-running investigation of Colonel Klein's role in the devastating attack.
The Bundestag inquiry has targeted Guttenberg over his initial claim that the air strike was “military appropriate” – a position he later reversed. He has since said he did not have access to information seen by his predecessor Franz Josef Jung when he declared the bombardment “militarily appropriate,” though media reports have contradicted that claim.
Guttenberg is due to face the parliamentary committee of inquiry on Thursday.
Schockenhoff added that Guttenberg's description of the attack as “militarily inappropriate” was unrelated to any criminal accusations against Colonel Klein.
“These questions must be considered independently of each other,” he said.
Greens MP and the UN's former Special Representative for Afghanistan, Tom Koenigs, rejected the call to wind up the committee of inquiry because he said there is evidence that information had been either deliberately or negligently concealed from the German public during the September election campaign.
Former Defence Minister Jung resigned from his new portfolio as Labour Minister in November, acknowledging he had mishandled the affair. Two senior defence officials also resigned.
Koenigs told broadcaster Deutschlandfunk that the clearing of Colonel Klein should not be misunderstood as a legitimisation of the attack. The bombing of the tankers may not have been a crime, but it was a mistake.
He could not understand, he added, why such a mistake had not led to a disciplinary proceeding within the military.
The comments came as daily Berliner Zeitung reported that the Berlin state prosecutor, Wolfgang Kaleck, planned to file an appeal against the federal prosecutor's decision. Kaleck is representing the human rights group ECCHR which, together with two lawyers from the German city of Bremen is acting for the families of the civilian victims of the attack.