(Reuters) -The deputy head of the Russian army's General Staff has been accused of taking bribes and arrested, investigators said on Thursday, the latest in a slew of high-profile cases of alleged corruption to shake the military's top brass.

The arrest of Lieutenant-General Vadim Shamarin is the fourth detention of a high-ranking defence figure within a month, starting on April 23 when Deputy Defence Minister Timur Ivanov was placed in pre-trial detention for suspected bribe-taking.

Since then, Lieutenant-General Yuri Kuznetsov, head of personnel at the defence ministry, and Major-General Ivan Popov, former commander of Russia's 58th army, have also been arrested.

Shamarin is accused of taking bribes between 2016 and 2023 from a factory in the Ural mountains that produces communications equipment, as a reward for placing bigger state contracts with it, Russia's Investigative Committee said. It said he had benefited to the tune of at least 36 million roubles ($400,000).

Shamarin, whose home was reportedly searched in connection with the investigation and who has been placed in pre-trial detention for two months, faces a prison term of up to 15 years if found guilty. There was no immediate word on how he pleaded.

Shamarin has been in charge since 2020 of overseeing the army's Signal Corps, which is responsible for military communications, including ensuring confidential battlefield command signals.

The arrests are the biggest scandal to hit the Russian army in years and come at a time when it is has regained the initiative on the battlefield in Ukraine and has a new defence minister, economist Andrei Belousov, at its helm.

The appointment of Belousov, who has no army experience, was widely seen, among other things, as a move to eliminate wastage and corruption in defence spending. Sergei Shoigu, the previous minister, has been moved to become secretary of Russia's Security Council.

With no obvious end in sight to the war, now well into its third year, the arrests appear to underpin a major effort to stamp out corruption surrounding the awarding of lucrative military contracts, to try to ensure that the military-industrial complex is producing as much as possible for the right price.

The Kremlin, which said it was not authorised to disclose details of the case, played down Shamarin's arrest and said similar anti-corruption work was being carried out across various Russian state agencies.

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

Other cases in other agencies are being pursued. On Thursday, investigators asked a Moscow court to place the deputy head of the Moscow region's prison service in pre-trial detention in a bribery case.

ANTI-CORRUPTION DRIVE

But Sergei Markov, a former Kremlin adviser, said Shamarin's arrest was the continuation of a sweeping shake-up among the army's top generals.

"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," said Markov.

He said one of the probe's aims was to "increase the army's morale and equip the army with modern communications equipment and missile and artillery guidance systems".

An influential military blogger close to the defence ministry who goes by the name "Rybar" and has over 1 million followers, said the arrest and others like it were logical, but that investigators had probably sat on the alleged wrongdoing for a long time before acting.

"And the result is an ideal situation for everyone," Rybar wrote on the Telegram app.

"The fighters at the front get a portion of positivity, the team of the new defence minister gets a loud start, the problems start to be solved immediately (it does not matter that the military-industrial complex and other components of the solution had already started to be put in place), and the ordinary population celebrates," he said.

Shamarin is a deputy to Valery Gerasimov, chief of the General Staff, who is managing the war in Ukraine. Gerasimov has not been accused of any wrongdoing, though he has at times faced harsh criticism over the performance of Russia's military since its full-scale invasion of Ukraine in February 2022, something Moscow calls a special military operation.

President Vladimir Putin said last week that he did not plan changes to the General Staff because "combat work" was going successfully.

($1 = 90.0870 roubles)

(Reporting by ReutersWriting by Andrew Osborn and Mark TrevelyanEditing by Frances Kerry)

By Andrew Osborn and Mark Trevelyan