Jaroslaw Kaczynski will be interviewed by military prosecutors in connection with the April plane crash in which his twin brother, then Polish president Lech Kaczynski, died.
Kaczynski, a runner-up in the country's recent snap presidential polls, lost his twin brother on April 10, when a presidential Tu-154 plane crashed in western Russia killing all 96 people onboard.
"Investigators are interested in all details related to the presidential plane crash," a lawyer representing interests of the accident's victims said.
The interview is scheduled for July 27.
"Naturally, investigators are interested in Jaroslaw Kaczynski, because he is the brother of the late Polish president," Rafal Rogalski told the media.
"Some members of the families of the Smolensk crash victims have already testified. Prosecutors ask them if they possess information which can be useful for the investigation into the cause of the catastrophe. They can choose themselves whether to be interrogated or not and when," Poland's thenews.pl English-language portal quoted Rogalski as saying.
All the relatives will also be officially informed about the possibility to claim damages, the portal reported.
A plane carrying Kaczynski, his wife, 88 officials and eight crew members, crashed en route to Smolensk after hitting trees as it attempted to land in thick fog. The high-ranking delegation was due to attend a memorial ceremony for the victims of the 1940 Katyn massacre in which Soviet secret police killed thousands of Polish military officers.
Russian and Polish investigators and experts are jointly investigating causes of the crash. Polish military prosecutors are conducting their own separate investigation.
WARSAW, July 10 (RIA Novosti)