MOSCOW, May 13 (RAPSI) - Sergei Mastyugin, ex-beneficiary of now-defunct Investbank, has been detained on suspicion of defrauding the bank of up to 800 million rubles ($16 million), Kommersant newspaper reported on Wednesday.

Olga Borgardt, acting board chairman of the bank, was detained earlier.

Both were initially witnesses in an embezzlement case that was opened in February 2014.

Investigators claim that Borgardt along with “unidentified individuals” transferred 1.5 billion rubles ($30,300) from Investbank to shadow companies.

Mastyugin allegedly instructed Borgardt to remove encumbrance from the stocks that secured loans of 200 and 600 million rubles ($4 mln and $12 mln) provided by Investbank to Dirrektiva company. The latter was allegedly under Masyugin’s control.

Mastyugin pleads not guilty, according to his lawyer, Sergei Dorokhin.

The operations of Investbank, the country's 84th largest bank by assets, were suspended on December 13, 2013.