A company has been ordered to recall two batches of radioactive dye after three patients received the wrong ones in a label mix-up. The Department of Health said it had received a report from Queen Mary Hospital on Thursday evening that three patients undergoing heart scans on that day were injected with radioactive dye designed for bone scans, Tc99mMDP, instead of the heart-scan dye Tc99mO4. Inquiries showed the staff of the dye supplier, Global Medical Solutions Hong Kong, had mistakenly put Tc99mMDP into containers labelled Tc99mO4. 'Adverse health effects on the three patients are not expected and they have not reported any,' a spokesman said. The hospital had arranged follow-up checks for the patients, he added. All public and private hospitals had been alerted but no other report relating to the products had been received, the spokesman said. The hospital had started an immediate investigation and required the company to adhere strictly to good manufacturing practice to prevent a recurrence, the spokesman said. The department would continue to closely monitor the recall and ensure the company put into place effective good manufacturing practices, the spokesman said.