Preliminary laboratory results were released on Friday in a foodborne illness investigation of a Santa Ana Bakery that distributed tainted bread.

According to the Orange County Health Care Agency, the results indicated the presence of a synthetic drug, which was used in making Rosca de Reyes bread at Cholula’s Bakery.

Officials explained more than 30 people reported experiencing dizziness, palpitations and numbness after eating the bread on Jan. 5 and 6.

The bakery will remain closed as part of the investigation until the business can show professional restaurant grade cleaning, disposal of all opened food and all ingredients used to make the bread, and mandatory food safety training for all staff.