In all, 12 of these cats have been taken in by the SPCA over the last two days. The animals appear to be unconscious, yet have muscular movements while in that state.

One of the cats died yesterday and its body has been sent to the Agri-Food and Veterinary Authority for a post-mortem to find out the cause of death.

The SPCA does not expect to get any results for at least a few days.

Its executive officer, Ms Deirdre Moss, said the case is beginning to look 'more and more suspect' with the discovery of more affected cats yesterday.

Canned cat food found at the foot of a block in Bayshore Park by an SPCA inspector has been sent to the Health Sciences Authority for tests, together with some blood samples from the cats.

A police report has been made by the residents. The SPCA is keeping the police updated regularly.

At least three cats under the SPCA's care are still in a comatose state and two of them are on intravenous drips. The rest of the cats are alert but many are still showing signs of disorientation.

Several of the cats are not in good shape, said Ms Moss.

'We still don't know what substance they've ingested and this is a big obstacle for us now.'

The Straits Times visited the condominium yesterday afternoon and spotted at least three cats roaming in the area. There were no traces of cat food left around.

Read the full story in Saturday's edition of The Straits Times.