Berlin's city hall deliberately placed troubled children in the care of paedophiles. From 1969 to 2003 the authorities put at least nine boys in the hands of convicted sex offenders on the advice of a disgraced social scientist. The idea behind the Kentler experiment named after Helmut Kentler, an academic who argued that paedophilia could have "positive consequences" " was that unruly and "feeble-minded" children would benefit from adult sexual attention. In the late 1960s Kentler persuaded West Berlin's ruling Senate that the homeless boys would jump at the opportunity to be fostered by paedophiles. One of the boys, referred to in legal proceedings as Marco, had been taken into care after suffering physical abuse at the hands of his father. In 1989, aged six, he was placed with a convicted child abuser. A year later this foster father, Fritz H, began going into Marco's room for a "cuddle". For ten years he was repeatedly beaten and raped by Fritz H. It is not known how many children were subjected to the Kentler experiment. Four years ago the Berlin Senate commissioned an inquiry into the scandal from experts at Göttingen University. Their final report has yet to be published. At the beginning of the experiment, Kentler, who died in 2008, was regarded as one of Germany's foremost sexologists and often appeared as an expert witness in court cases. He boasted of having secured the acquittal of several alleged paedophiles. In 1970 he urged the Bundestag to decriminalise sex between adults and children in West Germany.