A gang of neo-Nazis are on trial for raping and dismembering a suspected police informant while celebrating Hitler's birthday.

Evald Raats, 20, and Roman Kostin, 21, as well as two minors, aged 15 and 17, whose names have not been disclosed, have been charged with murder and will stand trial in the southwest Siberian city of Omsk, prosecutors said in a statement. Raats and Kostin are also being tried for rape.

Oxana Vladykina, 20, and Anton Chashchin, 21, are accused of "covering up an especially serious crime," the statement said.

At a party on the night of April 19, "a group of young people with nationalistic views were celebrating the birthday of Adolf Hitler," the prosecutor's office said.

The gang began to suspect a fellow reveler, identified as 24-year-old Andrei, of collaborating with police, and "Raats, Kostin and two underaged persons decided to kill him," the statement said.

Gazeta.ru reported that the victim had, in fact, provided information about the gang to police. Komsomolskaya Pravda wrote that he confessed during the party.

Raats and Kostin sexually assaulted the man and, together with the two teenagers, severely beat him, prosecutors said.

The "punishment" lasted more than four hours, Komsomolskaya Pravda wrote Thursday.

The 15-year-old reportedly took a knife to the victim's forehead and carved the word "musor," a slang word for "cop" that literally translates as "garbage."

Neighbors heard screams but did not call police because "the sound of music and someone shrieking was often coming from the apartment," the daily reported.

The gang allowed the accused three final requests before killing him. He asked for food, beer and 15 minutes alone, Gazeta.ru reported.

The man was then carried into the bathroom and decapitated. Raats, one of the alleged rapists, posed for photographs with the severed head, Komsomolskaya Pravda reported.

Some of the gang chopped up and bagged the body, then tossed it into a dumpster outside the building, the daily reported. Others cleaned up the mess.

A passer-by discovered the victim's legs dangling out of the dumpster and called the cops.