'They did not complain about the condition and the treatment given to the detainees at the centres.'

But the UNHCR says none of its officials have visited the camps, nor does it have anything to do with the deportation of irregular migrants.

'We do not review detention centres, we basically don't assess their standards and frankly nobody from this office, nobody from the UNHCR, has visited the Sabah detention camps,' Mr Lowell Martin, of the UNHCR in Kuala Lumpur, said.

'It must be a mistake. I'm disappointed. We are going to be looking into it, into how such a mistake could happen.'

Indonesians and Filipinos deported from the Sabah camps have told stories of alleged mistreatment and recent media coverage has focused on the alleged deaths of several infants.

The issue is becoming intensely divisive in the region, with government figures in Indonesia and the Philippines facing growing anger from their own citizens at the treatment meted out by Malaysia.

Mr Martin said the UNHCR was committed to assisting asylum seekers and refugees, not illegal migrants, and had been in touch with the Task Force in Sabah only on the issue of whether there were potential refugees among those detained.

He added: 'The answer was no.

'We work with them fairly closely, as there are refugees from an earlier period in Sabah, so we're hopeful that's correct.'

But on the subject of camp conditions, the government-sanctioned New Straits Times report 'seems to be a mistake', he said.

'We have not visited there, we are not in the business of assessing detention camps and are not involved in any way with deportation of irregular migrants,' he said.

Malaysia has received hundreds of thousands of legal and illegal migrants from its neighbours, seeking and finding work with employers chronically short of manual labour.

But the Malaysian government recently cracked down, imprisoning those migrants who outstayed a deadline and threatening them with caning and deportations.