Defence Minister Władysław Kosiniak-Kamysz closed the inquiry, which was started by the country's previous government and led by conservative politician Antoni Macierewicz, the defence ministry in Warsaw said in a statement.
It added that a team of experts would be appointed to "scrutinise every aspect" of the panel's operations.
Deputy Defence Minister Cezary Tomczyk told reporters that it was a "historic moment" that Poland would no longer "spend millions on activities that had nothing to do with explaining the circumstances of the Smolensk disaster."
He added that the panel's operation "had a lot to do with politics," public broadcaster Polish Radio's IAR news agency reported.
The so-called Smolensk Commission was established in 2016 by Macierewicz, who was Poland's defence minister at the time, the PAP news agency reported.
Earlier this year, the panel formally asked the prosecutor-general to investigate the 2010 disaster as a potential "premeditated assassination" of the Polish president and "murder" of the other people on board.
Tomczyk said on Friday that the Polish government stood by the findings of the original inquiry into the crash and a report released by the so-called Miller Commission in 2011.
The Miller Commission cited a catalogue of errors on the Polish side, while also pointing to errors made by Russian staff at the control tower of Smolensk Military Airport.
Presidential air disaster
The plane crash near Smolensk, western Russia, on April 10, 2010, killed Polish President Lech Kaczyński, his wife and dozens of top officials. It is still a source of controversy and recriminations.
The conservative Law and Justice (PiS) party, which governed Poland from 2015 until earlier this month, had challenged the Miller report.
The party's head, Jarosław Kaczyński, is the twin brother of the late President Lech Kaczyński.
Last year, the panel led by Macierewicz unveiled its findings in a 338-page report that claimed the 2010 disaster was caused by "at least two blasts" and by "political factors."
A Russian report had placed all the blame on the Poles.
(pm/gs)
Source: IAR, PAP, Radio Zet