She shows a natural aptitude for her work, sometimes breaking off a bottle to cut open the stomachs, gouge out the eyes or sever the ears and noses of the young men she is interrogating.
One of her aims is to get them to admit that they were snipers who fired at the Serbian forces. Such a confession means certain death, but in the circumstances death can be a welcome release.
An eye-witness account of what is happening inside the camp at Brcko, one of more than 100 said to be run by the Serbs, was given in London yesterday by a 50-year-old man who escaped two months ago.
His account cannot be independently verified, but will add to growing international concern about atrocities being committed in what was Yugoslavia. He called himself Mirsad for the interview because his family is still in Bosnia and would face reprisals if his identity was revealed.
Mirsad was arrested by Bosnian Serb forces in Brcko, which was 80 per cent Croat and Muslim, on 1 May. Thousands of local people were taken to warehouses in Luka, the town's harbour area on the river Sava.
He said: 'When we came to the camp we were kept in this big warehouse. Five hundred people were in our part of it and in the other part there were about 50 people training their machine guns on us.
'I was beaten. They stood me against the wall, put my hands up and then they beat me along the spine.' But the treatment that Mirsad received was mild compared with that meted out to the younger men.
The day after he was arrested three young men from the town of Zvornik in eastern Bosnia, who had been in the Bosnian armed forces, were terribly beaten. Mirsad watched them die from their injuries.
Alsatian dogs which had not been fed for days were set upon another group of young men. The victims screamed and wept as the animals bit them and eventually 10 of them died from the wounds that the dogs inflicted.
The Bosnian local police chief, a Croat, was brought into the camp covered in blood. The Serbs asked some of the prisoners if they would shoot him. Mirsad said that all those who were asked said they would not do it, and eventually the Serbs took the policeman away and killed him themselves. About 20 men who had refused to do it for them were also then removed and are presumed to have been shot.
The Serbs also carried out retaliation executions. Mirsad said that every time one of their soldiers was killed 10 Croat or Muslim civilians would be murdered.
Mirsad said that he personally saw 20 men die, and that every day 50 people were taken away from the camp never to return. He estimates that, including those murdered when the Serbs captured Brcko, as many as 5,000 people may have been killed in the area.
Those who remained in the camp suffered routine cruelty and received little food.
Monika Simonovitch, 18, a Bosnian Serb and the daughter of a local prostitute, arrived on the third day that Mirsad was there and was soon the most savage of the torturers.
He said: 'She was a very gentle-looking girl of medium height. We never expected her to be like that - in fact at first we were amazed and wondered what she was doing there.
'She was laughing, of course, she enjoyed it. That was particularly awful for us because then we saw what kind of people we were up against.'
On 31 May Mirsad was in a group of 10 men who rushed their guards at night, fled to the river 100 yards away and swam about 250 yards across to the opposite bank, which is in Croatia. Several of the escapers were shot dead.
After a short visit to Britain he will return to the Continent. He cannot go home because it is still occupied and he does not know if he will see his family again.
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