|The Polish president, his wife and 94 other mostly senior officials were killed on the way to a memorial [AFP]
Calling it "unacceptable", Poland's prime minister has rejected a Russian report on a plane crash in April that killed the country's former president along with dozens of top officials.
Donald Tusk criticised the draft report on the causes of the crash which Russia handed to Poland recently after conducting months-long investigation in an effort to mend long-strained bilateral ties.
Lech Kaczynski, the former president, his wife Maria and 94 others, mostly senior Polish officials, died on April 10 when their Tupolev-154 plane crashed in thick fog near Smolensk airport in western Russia.
"From the Polish point of view, the draft report from the Russian side as it has been sent is, without doubt, unacceptable," Tusk said in televised comments in Brussels on the sidelines of a EU summit.
He said the report does not comply fully with the Chicago Convention which regulates international air travel.
"This negligence and mistakes or lack of positive reaction to what Poland has been asking for, all these things allow us to say that some of the report's conclusions are without foundation," Tusk added.
In separate remarks, Tusk was also quoted by weekly magazine Polityka on Friday as saying the report downplays any Russian role in the accident.
"We have no reason to hide the Polish share of the responsibility for the disaster, and there is no doubt that the most of the real reasons are on the Polish side, but we also recognise that there were causes on the Russian side," he was quoted in Polityka.
In response the Inter-state Aviation Committee, Russia's civil aviation authority which drew up the report, said it will not comment on politicians' remarks on the investigation.
The Russian foreign ministry said the issue should not be "politicised".
"It stands to reason that Russian experts will reply to the Polish side's questions," the Interfax news agency quoted Alexei Sazonov, a ministry spokesman, as saying. "The main thing is not to politicise the situation."
On a visit to the Polish capital Warsaw last week, Dmitry Medvedev, the Russian president, promised to co-operate with Poland over the plane crash probe.
Russia is expected to study Poland's feedback on the report, which has not been made public, before trying to jointly write a conclusive version of what happened.
A Polish investigator, Edmund Klich, has said a combination of more than a dozen factors led to the crash, and that most of the mistakes were made by Poles.
He said, for instance, the Polish crew's decision to try to land in dense fog was "totally irrational".
But there are also questions surrounding why the Russian air traffic controllers did not order the plane to land elsewhere given the lack of visibility.
The two sides also disagree on whether the flight should be classified as military or civilian, a potentially crucial point in assigning responsibility for the decision to land in poor weather.
Kaczynski's identical twin brother Jaroslaw, who heads Poland's main opposition Law and Justice party, has accused Tusk and Russia of effectively engineering the crash and of collaborating to cover up its real causes.