Kenyans could be consuming contaminated bottled water after Kenya Bureau of Standards (Kebs) warned that 157 companies are operating illegally.
The agency Thursday said it cannot vouch for water from the firms as consumers increasingly cut reliance on tapped water.
The firms are said to operate in unhygienic sites, some lack Kebs certification and others are based in unknown locations.
Some of the companies are also accused of taping suspect water and misleading users with fake labelling.
Kebs managing director, Charles Ongwae, said the agency has started a crackdown on the firms.
"There are people who love shortcuts. Today we are announcing 157 water bottling firms that are operating illegally without valid product certification marks and have failed to meet required standards," said Mr Ongwae.
He did not, however, name the firms.
A recent global study revealed that world's leading brands of bottled water are contaminated with tiny plastic particles that are likely seeping in during the packaging process.