A HANDFUL of former Linc Energy executives are under scrutiny as part of investigations into allegations of wilful environmental damage on the Western Downs.

The State Government has confirmed 12 former executives of the failed underground gas company were being investigated, with notifications letters delivered late last month.

They are expected to be interviewed in coming weeks as part of investigations into allegations the failed gas company wilfully damaged the environment at its operations at Chinchilla on the Western Downs.

It comes as a landmark trial against the gas company is set to go ahead on five counts of wilfully causing serious environmental harm which breached the Environmental Protection Act.

It is understood the former executives being investigated are separate to the notice served on former Linc chief executive Peter Bond under the Chain of Responsibility laws.

The Department of Environment and Heritage Protection in May served Mr Bond with notice to stump up a $5 million bond to guarantee the Chinchilla gas site would be suitably rehabilitated.

A spokesman for the Department of Environment and Heritage Protection said the investigation of the former executives was separate to the application of the Chain of Responsibility laws.

Linc Energy creditors last month voted to liquidate the company.