GENEVA - The UN torture investigator said yesterday he was looking into allegations by the Falun Gong group that thousands of its followers were being held at a Chinese "concentration camp" and some had been killed. The banned spiritual movement said this month up to 6,000 people were kept at a state-run camp in the Sujiatun district of the northern city of Shenyang, where some had been killed and their organs sold. "The allegation is Falun Gong practitioners are being used for the sale of organs and human tissues ... According to the allegation nobody has so far left this concentration camp," said Manfred Nowak, UN special Rapporteur on torture and other cruel, inhuman or degrading treatment or punishment.