"Some witnesses have been questioned. They include wardens and inmates who fell victim to the poisoning," chief of the public relations section of the Badung district police, First Inspector I Ketut Oka Bawa, said on Wednesday.
The questioning of witnesses is still under way, he said adding, the police will conduct an in-depth investigation in the case.
The wardens and inmates who are being questioned are believed to have been present at the prison when the incident happened, he said.
"To be sure, all wardens will be questioned, particularly those who were there when the incident occurred," he added.
At least 21 inmates from the correctional facility were hospitalized after reportedly drinking disinfectant liquid mixed with orange juice powder last week.
While reconstructing the incident, police retrieved three bottles of different sizes that allegedly held the drink spiked with disinfectant.
"Based on the initial case reconstruction of the incident, we found three bottles used to drink (the disinfectant-laced juice). We still need to conduct a laboratory test to see what the result will look like," chief of the North Kuta police precinct, Adjunct Commissioner Putu Diah Kurniawandari, informed last Friday.
The police will conduct an in-depth investigation to see whether the incident was planned, she said. In addition, the police will look for those who mixed the drink after the investigation is complete, she added.
Following the poisoning, just eight inmates were taken to the Sanglah Regional General Hospital in Denpasar for treatment earlier, but one of them was pronounced dead, she said.
According to the chief of the Denpasar Female Correctional Facility, Lili, disinfectant was placed in each cell at the prison in accordance with the health protocols.
"We place disinfectant in each cell to spray it routinely, in accordance with the health protocols. However, they misused the disinfectant by mixing it with a nutritional item to drink,” Lili said.
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