Russian investigators on Friday questioned the country's ousted defence minister as part of one of the most high-profile corruption probes of President Vladimir Putin's 13-year rule.

The powerful Investigative Committee interrogated former defence minister Anatoly Serdyukov for about an hour as part of an enquiry into a suspected $100 million property scam.

Russian news reports said Serdyukov refused to answer questions citing the absence of his attorney due to illness.

Serdyukov retains his status as a witness in the probe and has been summoned again for questioning on January 11, Investigative Committee spokesman Vladimir Markin told Russian news agencies.

Putin dismissed Serdyukov -- appointed as Russia's first civilian defence minister in February 2007 -- last month amid Russian media allegations implicating him in an even bigger embezzlement scheme.

The Kremlin has repeatedly stressed its commitment to fighting deep-rooted corruption that has ravaged post-Soviet Russia and weakened the public's trust in the authorities.

But few senior officials have faced criminal enquiries under Putin.

Interfax said Serdyukov himself had ignored several requests to appear for questioning before giving his consent this week.

"He was asked to appear (for questioning) several times, but he simply ignored the orders," the news agency cited an unnamed source as saying.