Charges against the former directors of a major gas company have been dropped. 

The former directors of Linc Energy were charged in 2016 over a failed coal gasification project on the Western Downs.

The company's founder Peter Bond and several other former executives faced legal action over contamination at the company's underground coal gasification (UCG) site near Chinchilla between 2007 and 2013.

The directors were accused of failing to ensure Linc Energy complied with the Environmental Protection Act.

The matter was due to be heard in the District Court in Brisbane this month, but the Director of Public Prosecutions says proceedings against Mr Bond and Donald Schofield, Stephen Dumble, and Daryl Ratta will now be discontinued. 

Judge Leanne Clare SC has asked Crown Prosecutor Ralph Devlin QC to provide a reason for the decision for discontinuing court proceedings.

“Given the enormity of the prosecution and the cost and time, and also the impact on so many people, it calls for an explanation on the record,” she said.

Mr Devlin said the prosecution was no longer satisfied it could prove serious environmental harm on individual counts after rulings on key evidence in pre-trial hearings.

The Queensland Environment Minister Meaghan Scanlon says the state is considering its options.

“This outcome does not detract from the fact that Linc Energy committed serious environmental harm,” she said.

“[It was] a decision that was upheld by the courts in 2018 with the largest-ever penalty imposed of $4.5 million under Queensland law.”

Linc Energy went into liquidation in 2016, leaving the site to be managed by the Queensland government.

Local environmental groups have described the decision as “galling”.