Hong Kong authorities are facing mounting pressure to explain how a company offering more expensive bottled water and without an operating factory could win a tender, while a civil service union leader has said workers are now worried about their health and are buying their own supplies.

Lawmaker Doreen Kong Yuk-foon on Monday questioned the deadline of three months that the government had set for itself in its investigation to produce preliminary conclusions on its bottled water procurement process.

“There are a few very basic questions from residents and it should not take three months to tell us,” she told a radio programme.

“If you take too long to respond to residents, you will fail to assure them [of the government’s integrity].”

Kong said authorities should reveal how the company involved had entered the supplier list and whether due diligence had been conducted before the contract was awarded.