An environmental engineer has questioned Origin Energy’s assertion that gas bubbling in a Queensland river is a naturally occurring phenomenon.

A video by anti-coal seam gas group (CSG) Lock the Gates shows gas bubbling to the surface of the Condamine River near Chinchilla.

Origin Energy, which owns a number of test wells near the site, says it is a natural phenomenon caused by a shallow coal seam.

But CSG expert Dr Gavin Mudd from Monash University says “it beggars belief that there could be no contribution by industry”.

Dr Mudd says there is no evidence to support Origin’s claim and the case needs further investigation.

The Queensland Government says it is investigating the matter, and Dr Mudd says there is a lot of monitoring bore between the Condamine River and where the CSG projects are located.

He says he expects the gas leak is the result of CSG activity, but pinpointing the cause will be difficult.

“They need to go and test a lot of the groundwater bores in the region and make sure they test bores that are between the Condamine and where the coal seam gas activities are,” Mr Mudd said.

Dr Mudd says the CSG industry is poaching a lot of expertise from the Government.