Polish prosecutors said on Monday that new evidence into the 2010 plane crash near Smolensk in western Russia suggested that two Russian air traffic controllers and a third official in the control tower had deliberately contributed to the accident.

According to the prosecutors, the evidence was taken from recorded conversations between the plane's pilots and the Russian controllers. However, the prosecutors said that no further details could be revealed before investigators had questioned the three men implicated in the probe.

The crash in April 2010 killed Polish President Lech Kaczynski and his wife, as well as the country's central bank chief, a number of high ranking military chief of staff and several lawmakers. The officials were headed to Russia's Katyn forest to commemorate the 22,000 Polish officers executed by Soviet secret police in 1940 - a massacre the Kremlin denied until 1990.

Jaroslaw Kaczynski has given a voice to numerous of accusations and conspiracy theories around the 2010 crash.

Although previous enquiries attributed the disaster to human error and bad weather, Poland's Law and Justice (PiS) party, led by Kaczynski's twin bother Jaroslaw, believes the crash was deliberate and has been conducting its own probe.

Jaroslaw Kaczynski has made a range of allegations about to crash, suggesting that there was an explosive onboard, that Russian President Vladimir Putin ordered the assassination and that former premier and current EU Council President Donald Tusk was complicit in the orchestrating the crash and hindering the subsequent investigation.

"An analysis of the evidence ... has allowed prosecutors to formulate new charges against air traffic controllers, citizens of the Russian Federation," Polish Deputy Prosecutor General Marek Pasionek told a news conference. The individuals implicated in the probe were guilty of "deliberately causing a catastrophe... that resulted in the deaths of many people," he said.

The Polish government had already pressed charges against the two air traffic controllers in 2015, one for "being directly responsible for having endangered air traffic" and the other for "unintentionally causing an air traffic disaster." The latest charges, however, are much more serious, suggesting the men had deliberately sought to crash the plane.

Kaczynski and his wife Maria are buried in the crypt of the Wawel royal castle in Krakow where the kings of Poland are also interred.

Russia disputes accusations

The Russian government responded quickly to reject the PiS' accusations. Kremlin spokesman Dmitry Peskov told reporters Monday that "of course we cannot agree with such statements."

"You know that an investigation is also ongoing on the Russian side. The circumstances of this tragedy, this catastrophe, are already very well elucidated and investigated," he said.

A previous Russia-led investigation into the crash found that the fault lay exclusively with the Polish pilot, placing no blame on the Russian air controllers.

The Polish government has also repeatedly called on Moscow to return the plane wreckage, something Russia says it will only do once it has completed its own inquiry into the accident.

However, Polish prosecutors said that fragments of the plane would be sent to labs abroad to check of evidence of explosives, while justice officials have also been exhuming the victims' remains to establish the cause of death.

Watch video 01:01 Poland is in mourning - The people in Poland are in schock after the death of president Lech Kaczyinski in a plane crash

dm/rc (AP, Reuters, AFP)