According to the Jakarta Post, East Java police questioned 67 witnesses to the well control incident that occurred on May 29 before naming the nine, who are expected to be charged over the failure to protect the environment during drilling operations.

It was not clear when the nine would face court.

According to the paper, the mudflows from the well are increasing with around 50,000 cubic meters of toxic, hot, foul-smelling mud spouted each day. The mud has submerged four villages, rice fields and several factories, with around 10,000 villagers said to be homeless.

Last week, two people were injured after a violent explosion from the well shot hot mud high into the air.

Also last week, Indrasurya Mochtar, head of the nearby Surabaya Institute of Technology’s civil engineering school, told the paper he believed there was a chance the mudflow was unstoppable and would only get worse.

“In view of the current situation, I predict that within two weeks to one month, the ponds will break apart and millions of cubic metres of mudflow will spill out, inundating more areas,” he said.

Australian oil and gas major Santos holds an 18% stake in the well and has previously informed the Australian Stock Exchange that it holds “appropriate insurance coverage for these types of occurrences”.