Lieutenant-General Vadim Shamarin, who also heads the main communications directorate at Russia’s defense ministry, was taken into two months pre-trial detention on the orders of a military court on Wednesday, the state-run TASS news agency reported.

Reuters wrote on Thursday that a senior defense ministry procurement official, Vladimir Verteletsky, had also been arrested, bringing the crackdown’s head count to five in a month.

On April 23, a deputy defense minister, Timur Ivanov, was placed under arrest on suspicion of taking bribes in an investigation into allegations of graft in the awarding of lucrative military contracts. Ivanov was a close associate of the former defense minister, Sergei Shoigu, who was ousted in May.

Earlier in the month, a former top commander of Russian forces in Ukraine, Major-General Ivan Popov, was arrested and charged with accepting bribes. He was released on house arrest on Friday.

The head of the defense ministry’s personnel department, Lieutenant-General Yuri Kuznetsov, has also been detained as part of the anti-bribery drive, the biggest scandal to hit the Russian military for years, coming at a time when its forces are making gains in Ukraine.

The Kremlin said the arrests were part of a wider-scale clean-up across state agencies.

"The fight against corruption is consistent work," Kremlin spokesman Dmitry Peskov told reporters, as quoted by Reuters. "It is not a campaign, it is constantly ongoing work."

Lieutenant-General Shamarin stands accused of accepting bribes to the tune of $400,000 between 2016 and 2023, according to Russia's Investigative Committee. Investigators said he took kick-backs from a factory in the Ural mountains that makes communications equipment.

If found guilty, he faces a prison term of up to 15 years. He has pleaded not guilty, according to TASS.

Investigators said Verteletsky, the procurement official, had been charged with abusing his position. They allege that in 2022, he signed off on a contract that had not been completed in full, costing the state $764,000.

A Kremlin insider told Reuters that Shamarin’s arrest was part of a shake-up of Russia’s top military brass.

"The arrest of Shamarin, deputy chief of the General Staff, is not only an arrest, but also a large-scale audit of the work of the Main Communications (Signals) Directorate by the Audit Chamber," Sergei Markov, a former Kremlin adviser, told the news agency, adding that the crackdown was intended to "increase the army's morale and equip the army with modern communications equipment and missile and artillery guidance systems".