The operators of a popular Korean barbecue restaurant in Darwin could face fines of up to $18 million after being charged over an explosion that injured five diners earlier this year.

Emergency services were called to Little Miss Korea on Austin Lane in the CBD after the customers suffered burns when butane gas ignited under their table on the evening of September 7.

The Northern Territory’s work safety watchdog has now charged the family partnership operating the venue with six breaches of the Work Health and Safety Act.

NT WorkSafe said the group of men had been cooking food on a barbecue grill unit using coal.

The grill unit was also fitted with a butane gas canister, which was not being used at the time, but had a vent designed to release gas if it became over-pressured.

“NT WorkSafe will allege that the close proximity of the hot coals to the butane gas canister caused the canister to overpressure, activating the [vent] and releasing the butane gas under the table,” it said in a statement.

The build-up of butane gas subsequently ignited causing the injuries, it said.

“NT WorkSafe will further allege that despite clear warning signs on the butane gas canister, none of Little Miss Korea’s safety information, including staff safety induction, standard operating procedures, risk assessment or work health and safety policies, provided any safety advice or instruction to staff on the gas cartridge compartment of the barbecue grill unit or use of butane gas canisters.”

The safety watchdog also said the barbecue grill unit allegedly lacked evidence that it had been certified for use in Australia, as required by law.

NT WorkSafe said the family partnership, CJ Lee and DJ Lee, faces six reckless conduct charges for allegedly “failing to comply with their primary duty of care to ensure the safety of their patrons”.

If found guilty of all charges, the maximum combined penalty would be $18 million.

The case is expected to go before the Darwin Local Court on January 31 next year.