A batch of Valium tablets which left 14 people needing hospital treatment were "stronger than normal", tests have found.
Emergency warnings were issued by police and health experts after people in Fort William suffered extreme reactions at the weekend after taking the small blue tablets.
Fourteen people, mostly aged between 19 and 24, were admitted to the town's Belford Hospital for treatment.
Tests on the bad batch of tablets have revealed that they are diazepam - or Valium - but stronger than normal.
Symptoms suffered by people who have taken them include unconsciousness, unresponsiveness and feelings of nausea and dizziness.
Despite the warnings, Northern Constabulary say they are still finding people who have the tablets and some who are continuing to use them.
A 22-year-old man has been charged over the incident and is expected to appear in court shortly.
Police and NHS Highland staff are urging people not to take tablets which have not been prescribed by their doctor.
Anyone with tablets they are worried about can take them to Fort William police station or Belford Hospital, or phone NHS 24 on 08454 242424.