A source, who wished to remain anonymous, told ILN the resignations included Integra general manager Steve Kovac, Integra underground operations manager Gerald Linde and Integra open cut operations manager Mick Gallagos.

Integra’s David Webb, part of the executive management team, is also believed to have resigned, along with Vale’s group manager for health and safety in Australia Geoff Mackenzie.

There have been other resignations at the mine in recent months which have included the financial controller along with technical services personnel, according to the source.

ILN has sought comment and confirmation from Vale Australia for several weeks but has not received a response.

However, the company typically does not comment on staff movements, citing privacy reasons.

A company spokesperson previously told ILN that Vale had recruited 197 new employees in the first five months of 2011.

“As with any organisation of Vale’s size, in the context of a volatile skills demand, some staff movement is inevitable,” the spokesperson said last month.

“Vale believes that our employees are our greatest asset and we place a high priority on developing and retaining qualified professionals.

“Vale recognises and empowers its staff, offering attractive career development opportunities and competitive benefits with a focus on a respectful and safe workplace.”