Former Defense Minister Anatoly Serdyukov on Friday appeared to anger investigators when he refused to answer their questions about fraud at the ministry.
Serdyukov reported for questioning but declined to do anything more than submit his written explanation of the way the ministry sold its property when he was in charge, the Investigative Committee said in a statement.
The committee is looking into several such sales on suspicion of fraud, and summoned Serdyukov, who stepped down as minister at the end of last year, as a witness.
Serdyukov cited a constitutional provision that allows people to withold evidence against themselves or their close relatives, a stance that is "no doubt legal but bewildering to the investigation, to say the least," the statement said.
"The position of the former defense minister may be construed by the investigation as a desire to deter the inquiry," the committee stated.
It said investigators will have to make up for Serdyukov's answers by collecting evidence otherwise, talking to more witnesses and doing research. Ultimately, Serdyukov could become a suspect, the statement hinted.
"It is quite probable that Serdyukov's procedural status may change in the course of the investigation," the statement said.
Serdyukov refused to talk at the previous questioning because his lawyer was sick.
The committee is investigating the sales of buildings that housed military institutes, land plots in the fertile Krasnodar region, a hotel and a store in Moscow, an oil terminal in Murmansk and so on.
Investigators believe that the ministry tentatively fell short of at least 4 billion rubles in revenues from these sales, compared with the fair value of the assets.