TAIPEI, July 29 -- The driver of a bus that caught fire in Taiwan on July 19, killing 26 people, is confirmed to have been driving under the influence of alcohol, local authorities said Friday.

Wang Yi-wen, deputy chief prosecutor of the Taoyuan District Prosecutors Office, told the press that investigators drew the conclusion after analysis of his blood, urine and stomach contents.

According to prosecutors, the driver's blood alcohol content (BAC) level was 0.215 percent, far surpassing the 0.05-percent legal threshold according to local regulations.

Wang said the case was serious and the driver had committed a crime.

Drugs, including opium and sleeping pills, were not detected during the analysis, according to investigators.

Everyone on board the bus was killed when it crashed into a highway barrier and caught fire near Taoyuan Airport. They included 23 tourists and a tour guide from the Chinese mainland, a local driver and a local tour guide.

Investigators said they will work to identify whether the driver's intoxication was linked to the cause of the deadly fire.