The Queensland Government has charged five former executives of Linc Energy with environmental offences over the failed company's alleged contamination of huge swathes of prime farmland in the state's south-east.

Key points: Charges related to alleged contamination caused by underground coal gasification

Charges related to alleged contamination caused by underground coal gasification Four other former Linc executives also summonsed

Four other former Linc executives also summonsed Company has denied the charges

The charges relate to the alleged contamination caused by Linc Energy's underground coal gasification (UCG) operation near Chinchilla from 2007 to 2013.

Linc Energy's founder and former chief executive Peter Bond was charged in September with three indictable offences of failing to ensure Linc Energy complied with the Environmental Protection Act.

The ABC has been told Mr Bond has now been summonsed on two further charges.

Four other former Linc executives have also been summonsed.

The company itself, which is now in liquidation with estimated debts of $300 million, is facing five charges of wilfully and unlawfully causing serious environmental harm.

Linc Energy's founder and former chief executive Peter Bond was charged in September. ( AAP: Andrew Taylor )

The ABC revealed last year that a Queensland Government investigation found hundreds of square kilometres of prime agricultural land was at risk from a cocktail of toxic chemicals and explosive gases that had allegedly seeped from Linc's UCG site.

The multi-million-dollar investigation was the largest in the Queensland Environment Department's history.

It found that soil near the facility had been permanently acidified, with methane, hydrogen, carbon monoxide and hydrogen sulphide alleged to have leaked from the site.

At committal proceedings last year, the Dalby Magistrates Court was told workers at the site had also been exposed to "significant concentrations" of gases, with some claiming they fell ill after being exposed.

The company denied the charges, but has been committed to stand trial at a date to be set.

'Possible' more charges could be laid

As well as Mr Bond, the ABC has been told that four former Linc Energy executives have now been summonsed on charges of failing to ensure the company complied with the Environmental Protection Act.

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The former executives are:

Donald Schofield, former Linc Energy general manager, on two charges

Donald Schofield, former Linc Energy general manager, on two charges Stephen Dumble, former chief operating officer, on two charges

Stephen Dumble, former chief operating officer, on two charges Jacobus (Kobus) Terblanche, former chief operating officer, on one charge

Jacobus (Kobus) Terblanche, former chief operating officer, on one charge Daryl Rattai, former general manager, on one charge

They are expected to appear at the Dalby Magistrates Court on November 29.

Penalties for individuals convicted of these offences can be up to five years' jail.

If convicted, the total maximum penalty for the charges against Linc Energy is $8,850,000.

"Queensland's Environment Department is continuing its formal investigation into the activities of Linc Energy and it's possible more charges could be laid," Environment Minister Steven Miles said.

"As investigations remain active, and as this matter is now before the courts, the Government won't comment further on the details of the current charges."

The ABC revealed in June that 12 former Linc Energy executives were under investigation by the Environment Department.