The number of crimes has been growing by 2.4 percent a year, with millions of wrongdoings going unreported, the group said in a mammoth 840-page volume that took 10 years to produce and was published last week.

In contrast, Investigative Committee head Alexander Bastrykin reported in October that the number of crimes in 2010 had plummeted by 13 percent.

Official statistics show a drop in the number of murders — from 34,200 in 2001 to 18,200 in 2009 — but they only reflect the number of criminal cases that were opened, the study said.

Taking into account reported murders where no cases were opened, the figure would stand at 46,200 for 2009, the group said. But even this figure appears incomplete, considering there were 77,900 unidentified dead bodies found that year and another 48,500 people were reported missing.

Academy professor Sergei Inshakov, who headed the research group, declined to comment Friday, saying only that “everything can be found in the book.”

Calls to the Interior Ministry's press service went unanswered.

Prosecutor General Yury Chaika indirectly acknowledged the problem last year, telling the Federation Council in April that while the number of registered crimes had dropped by almost 7 percent from 2008 to 2009, the number of reported crimes that police had refused to register was growing, the judicial news agency Rapsi reported.

Vladimir Ovchinsky, an adviser to the Constitutional Court's chief justice, said on Radio Liberty on Thursday that the large gap between official and actual statistics has been confirmed by numerous other research papers whose authors “came to roughly similar conclusions using different methods.”

Viktor Ilyukhin, a Communist deputy on the State Duma's Security Committee, said the latest study “almost completely” reflects the current state of affairs in the country. “The level of unreported crimes is very high,” Ilyukhin said by telephone. “Unreported crimes existed and will exist, while their quantity is an indicator of the work of law enforcement agencies."

The study echoes President Dmitry Medvedev's criticism of official statistics on crimes in the North Caucasus, which he called “nonsense” in November.

Medvedev has initiated an overhaul of the country's law enforcement system, widely viewed as corrupt and ineffective, by introducing bills to reform the police force and separate the Investigative Committee from the Prosecutor General's Office.