A spokesman for the prosecutor general said the investigation began when a military commander reported that foreign credit cards had been confiscated from men in his unit, Itar-Tass reported. Investigators say the four had at least four cards and used them to steal about $2,000, although one was swallowed by a bank ATM machine.
A spokesman for Defense Minister Alexei Kuznetsov said the money will be repaid and the victims issued a formal apology if the draftees are convicted.
President Lech Kaczynski, his wife and many top officials in his government were killed April 10 when the plane crashed as it approached Smolensk. All 96 people on board died.
The president was on his way to a commemoration of the Katyn Forest Massacre, the World War II slaughter of Polish soldiers by the Soviet Army.
The Interstate Aviation Committee, which is investigating the crash, is trying to identify several people who were in the cockpit at the time but were not members of the flight crew, RIA Novosti said. One has been determined to be Polish Air Force Chief Andrzej Blasik, and officials said Tuesday they had identified another voice, although they did not release the name.