A suspected hydrogen sulphide gas leak at a paper mill killed two workers and left a third in a critical condition.

Emergency crews responded to the call at Norske Skog mill at Ettamogah, on the border of Victoria and New South Wales, early on Thursday afternoon.  They rushed the patients to Albury Base Hospital; a 28-year old man died there on Thursday, and a 33-year old man died overnight.  One patient is in a critical condition, and another was in a stable condition; a further 15 workers were released from hospital.

Exposure to high concentrations of hydrogen sulphide can result in excess fluid in the lungs, known as pulmonary edema. 

"The injuries and related fallout from what occurred yesterday is consistent with that gas, but still needs to be established," said Scott Kidd of Safe Work NSW.

A Norske Skog spokesman said teh company is co-operating with SafeWork NSW's investigation.

"Our first concern is to our employees, their families and everyone affected by this tragic accident," said General manager Milo Foster, "We will provide support to those affected and work with authorities to investigate what happened."