Worried consumers streamed into pharmacies to return Marching Pharmaceutical Ltd (MPL) products yesterday after the Hong Kong-based drug manufacturer had its licence revoked amid an investigation into allegations it forged product reports. Police arrested four MPL staff members, one man and three women aged 25 to 58, on Thursday on suspicion of forgery. They were released yesterday on bail of HK$10,000 each and told to report back to police next month. The MPL product recall, ordered by health authorities, and one-month licence suspension are the latest developments in two controversies involving local drug makers in the past week that have sparked public concerns about the regulatory system. Consumers can return drugs made by MPL to the pharmacies where they were purchased, or to one of the three designated dispensaries in San Po Kong, Cheung Sha Wan and Tai Po. Yesterday, some customers travelled all the way from Macau to return MPL products. At the Tai Wah Dispensary in Cheung Sha Wan, shopkeeper Wong Yuet-yau said a couple working for a Macau hospital had returned four bottles of cough syrup that 'is not even sold in Hong Kong'. He still offered a refund. Another man, who returned four packets of flu pills, said he had lost confidence in local drug manufacturers and from now on he would buy drugs imported from overseas. 'The production quality of local drug makers is deteriorating so much that it is almost on a par with that of scam companies on the mainland.' At the Wonder Dispensary in San Po Kong - one of the three designated pharmacies - the shopkeeper said there had been no signs of panic. However, Lau Oi-kwok, chairman of the Hong Kong General Chamber of Pharmacy, complained that MPL had not told members what to do with the returned drugs. MPL came under scrutiny on February 25 when the Department of Health discovered it was distributing pharmaceutical products with an indicated shelf life of three years when they only had a two-year shelf life. The Hospital Authority said yesterday that it only used two products manufactured by MPL - a medicated skin cream and a potassium solution for intravenous use. Both items would be replaced, it said. Marching was founded in 1968 as a dispensary and pharmaceutical wholesaler. In 1984, the company was reorganised into a corporation and named Marching Pharmaceutical Ltd, according to information on its website. In 2002, it was issued a certificate for good manufacturing practices. According to company registration records, some of its shareholders also own Jing Du Yang Sheng Tang Chinese Herbal Manufacturing, Yang Sheng Tang Pharmaceutical, and Worldwide Resources Pharmaceutical. A Department of Health spokeswoman said its probe did not cover them.