Hundreds of illegal immigrants held in a detention centre on the Greek island of Lesbos have fallen ill after drinking contaminated water from rusty and mouldy pipes, police said yesterday.

Police said hospital staff rushed to provide emergency medication after the weekend incident at the centre, where medical charity Doctors Without Borders (MSF) denounced a "humanitarian crisis" in July.

"Almost all of the immigrants at the detention centre have been poisoned," a police official said.

"They are in a bad condition, but they cannot be transferred to hospital as they are too many and in a bad state," the official said.

About 600 illegal immigrants were detained on the eastern Aegean island. The police official said water pipes at the centre were old and toilets were not working properly.

Greece has been criticised internationally for the poor conditions in its six detention centres and its harsh treatment of migrants who arrived in Greece without identity papers to seek asylum from war-torn countries such as Afghanistan.