Russian investigators on Thursday searched the offices of a defence ministry holding company, in a highly unusual move after opening a criminal probe into a suspected $100 million property scam.

Officials from the Russian Investigative Committee raided the offices of Oboronservis, a company wholly controlled by the defence ministry whose operations range from weapons maintenance to agriculture to publishing.

The Investigative Committee said in a statement that it had opened five criminal cases into suspected fraud in the sale of property, land and shares belonging to Oboronservis.

The unnamed officials targeted in the probe are suspected of causing losses of around 3 billion rubles ($100 million) to the Russian budget by selling properties well below market value.

"As part of the criminal case, investigators are searching Orboronservis offices, confiscating documents and interrogating officials," the Investigative Committee said in its statement.

The Interfax news agency quoted security sources as saying that two people had been arrested and the searches were still ongoing.

Oboronservis was created in its current form by a Kremlin decree in 2008 as part of a large-scale reform of the Russian military, bundling together nine defence ministry sub-holdings with the aim of helping the ministry focus on its core work.

In a sign of the seriousness of the case, Russian media said Defence Minister Anatoly Serdyukov who has spearheaded the military reform was present at the scene of the search.

Serdyukov said in a statement that the defence ministry wanted to see a full investigation but emphasised that the figures presented by the Investigative Committee were no more than "theories" until the investigation was over.

A former furniture salesman who rose to head the Russian tax authority, Serdyukov became the first civilian to serve as post-Soviet Russia's defence minister when he was appointed in 2007.

His lack of military credentials and controversial military reform programme have made powerful enemies within the defence ministry but analysts believe he still enjoys strong Kremlin backing to push through the army overhaul.

The head of the defence commission of Russia's Social Chamber oversight body, Alexander Kanshin, said that the problems at the Oboronservis showed up a lack of financial discipline at the ministry under Serdyukov.

"The problem with the defence chief is that he has concentrated a lot of functions around himself, including 20 departments and sections. Clearly, it is hard to control the system that he has created himself," he said according to Interfax.

Alexei Pushkov, the head of the lower house of parliament's foreign affairs committee, was even more blunt.

"Defence ministry officials have been accused of property scams. Somehow this is not particularly surprising. They question is -- how high up will it go?" he wrote on Twitter.