The Association of Professional Engineers Scientists and Managers Australia (APESMA) says that BHP Billiton is employing aggressive tactics to lock out workers from its Appin mine in Wollongong, Australia.

APESMA is a union that represents white collar miners in the country and is currently in the midst of a dispute with the mining company over wages and work conditions.

The union seeks to resolve the dispute amicably, but BHP claims that supervisors sought an unrealistic 27% pay rise and locked workers out to curtail operational disruption.

APESMA has, however alleged that the company is trying to force the supervisors into a four year agreement with no annual pay rise.

APESMA CEO Chris Walton was quoted by ABC News as saying that around 52 mine supervisors will be locked out if the company goes ahead with its decision.

"These strong arm tactics are designed to intimidate those workers rather than constructively resolve this dispute," Walton added.

BHP Billiton External Affairs head John Brannon revealed that the company is not yet prepared to refer the dispute to Fairwork Australia.

"We still remain of the view that the parties should work this issue out and we remain confident that we’ll be able to do so," Brannon opined.