The Interior Ministry pledged on Monday to investigate complaints by a group of OMON riot police officers about being forced to make false arrests and to work with fellow officers who held second jobs as bodyguards for gangsters.

Moscow police, meanwhile, flatly denied the allegations.

OMON officers are being hired by private businesses to offer protection for everyone from mafia bosses to the owners of fast-food kiosks, the opposition New Times reported Monday, citing officers who had appealed to the magazine.

"One of us once protected a shwarma place outside a hotel in [Moscow's] Ismailov [district]. … On Arbat, we guard the office of a Georgian thief-in-law," one officer told the magazine, explaining that his battalion commander tolerated illegal side jobs in exchange for a share of the proceeds.

The officers also said they were press-ganged into arresting innocent people because of orders to make at least three detentions per shift. Otherwise they risked seeing their monthly salaries of 26,000 rubles ($850) being cut by 10,000 rubles, the report said.

Because of this, 12 of the weekly detainees in the Kitai-Gorod district are homeless people arrested for petty crimes, the officer said.

The police officers took the highly unusual step of publicizing their complaints after they received no reaction to a letter sent to President Dmitry Medvedev, the report said.

The letter, copies of which were also sent to the Interior Ministry and the Prosecutor General's Office, was signed by "about a dozen" members of the city's second OMON battalion, five of whom the New Times identified.

A Kremlin spokesman said Monday that he could not say whether the letter had been received.

First Deputy Interior Minister Mikhail Sukhodolsky said the allegations would be carefully investigated.

"In the unlikely case that they are confirmed, those responsible will have to face the most serious consequences," Sukhodolsky said, Interfax reported.

Moscow police, however, described the allegations as "slander" by disgruntled officers who had been fired. "We have repeatedly received such allegations. An internal investigation of these latest complaints did not confirm them, and they are clearly slander," police spokeswoman Zhanna Ozhimina told Interfax.

She said four of the five officers identified in the report had been fired for various criminal and disciplinary offenses last year. The fifth, she said, had never served with the OMON.

But New Times reporter Ilya Barabanov, who co-authored the article, told The Moscow Times that he had seen the officers' badges and suggested that the dismissals had been backdated.

He said the police officers whom he had interviewed had told of recruits having to sign undated dismissal orders that were kept in the battalion commander's safe. "The fact that they now take them out and put a suitable date on them just illustrates the system's deficiencies," Barabanov said.

Barabanov said he expected that the whistleblowers, who had approached him at a recent meeting with police trade union members, would face punishment. "Appealing to journalists was a desperate and last step for them. I do not exclude that they will end up like Dymovsky," he said.

Alexei Dymovsky, a former police major from Novorossiisk, made similar corruption allegations and posted appeals to Prime Minister Vladimir Putin that surfaced on YouTube in November. Dymovsky was fired, charged with abuse of office and taken into pretrial detention last month on accusations that his calls were trumped up.

The OMON case is more notable because, unlike Dymovsky, the officers openly blame their battalion commander for permitting illegal activities, said Andrei Soldatov, a security expert who heads the Agentura.ru think tank.

"This is very important because it provides an opportunity to check their allegations," Soldatov said.