According to the ABC, BHP issued a writ with the Supreme Court last week seeking damages of up to $A7 million over the incident.

While a BHP spokesman could not comment on the matter as it was before the courts,

MiningNews.net understands the writ was regarding an incident which occurred on March 9 this year, where an illegal strike took place involving its contractors tug operator.

It's being claimed that MUA WA branch secretary Will Tracey instructed employees of Teekay Shipping Australia to not attend work.

As a result, it's understood Teekay was unable to perform normal duties for four hours.

Since BHP has a contract with Teekay to operate and maintain the tugboats at the Port, with the employees of Teekay being covered by an in-term labour agreement, BHP reportedly claimed the stoppage was illegal and caused loss to the business.

BHP intends to seek damages through a third party damages claim.

Tracey told MNN that the MUA was in the process of seeking legal advice, with plans to defend the lawsuit.

He was not aware of Teekay's intentions to sue.