The Health Sciences Authority (HSA) has ruled out defects in manufacturing and product quality in a case in which a 55-year-old man was hospitalised after drinking a herbal remedy to aid indigestion.

HSA said after rigorous physical and lab testing of all the bottles of Sri Ambikkas Omum Water it had quarantined, it found no other sample with high alkalinity.

It is working with the importer to lift the quarantine and sales suspension of the product, which is made in Malaysia, it said yesterday.

Mr Gunalan Perumal had injuries and swelling in his mouth and throat on Aug 3 after drinking from a bottle of the water. He was in intensive care for three days. It was found that the omum water he had consumed had a pH level of over 13 - equivalent to levels in chlorine bleach.

HSA was alerted and it stopped all sales and import of the product.

However, it said preliminary testing suggested it was an isolated incident. No other similar adverse reports of the product have been made. It said yesterday: "Based on HSA's scientific assessment, we have ruled out product defects, which refer to issues with the manufacture of the product resulting in the product being of inadequate quality or unsafe."

When contacted, a Sri Ambikkas spokesman said the move to get the product back on the shelves is being reviewed. "We were confident from the start it's not a product problem. But nonetheless, it's welcome news from the authorities."

HSA made a police report after it concluded investigations. The police said there was no evidence to suggest foul play.