It sounds like the plot to a thriller by Martin Cruz Smith, author of Gorky Park, but there is nothing fictional about these killings. The Russian media have nicknamed the killer 'the Bitsevsky Maniac' because the murders have all taken place in Moscow's Bitsevsky Park.

Since October last year, police have recovered 16 bodies from the heavily forested park. The 16th corpse, that of a well-dressed and so far unidentified young woman, was found on Wednesday. Small wooden stakes had reportedly been driven into her eyeballs and she had been battered on the head with a heavy object.

Police say at least nine of the 16 murders are the work of the 'maniac'.

The others are believed to be the work of different killers. 'The maniac' follows a well-established pattern: until now his or her victims were all men aged 50 to 70 and were all killed by a blow to the back of the head with a heavy object. The killer always strikes in the evening or at night and does not kill for financial gain, never taking the victim's money.

The men killed so far were poor pensioners or homeless people. Police believe the killer befriends the victims by offering them alcohol.

Muscovites suspect the murderer is a patient from a hospital for the psychologically disturbed located in the park close to where most of the bodies were found. The hospital says it cannot rule out the possibility.

The 'maniac' is described as being powerfully built, though police have not ruled out the possibility it is a woman. Twice the police have detained (and in one case shot) suspects only to let them go for lack of evidence. The first pulled a knife on them when confronted and ran off . . .

he later said he thought the police were trying to mug him. The second was a transvestite who had a hammer in a handbag. Police thought they had their man, but the transvestite had a solid alibi and was released.

The police have set up a task force to catch the killer and have plainclothes officers patrolling the park.