Mirvac is probing tax treatment of James MacKenzie's fringe benefits MIRVAC Group is investigating the company's taxation treatment of fringe benefits received by chairman James MacKenzie. The move comes in the wake of Mr MacKenzie last week flagging his intention to retire at Mirvac's annual general meeting in November, after chairing the company for almost eight years. Mirvac's tax treatment of the chairman's accommodation allowances while running the Sydney-based group for several months last year are thought to be at issue. Mr MacKenzie gave no indication last week about the matter, saying he felt it was the right time to hand the mantle to someone new. But the chairman, who came under fire last year from Mirvac investors over the sudden departure of former boss Nick Collishaw, has faced questions about the subsequent departure of ex-CFO Greg Dwyer and other executives leaving. The Australian was told yesterday that Mr Collishaw's departure was not prompted by strategy disagreements but rather by disputes over expenses. Mr MacKenzie has previously attributed Mr Collishaw's poor communication of Mirvac's strategy for his departure. Mr Dwyer's more recent departure also prompted claims he had challenged some of Mr MacKenzie's spending at board level. Mirvac has rejected these accounts, but investors were concerned when Mr MacKenzie became an executive director between August 24 and November 5 last year to oversee the transition to incoming chief executive Susan Lloyd-Hurwitz. Mr MacKenzie com, who is also the Yancoal co-vice chairman and recently retired from the Pacific Brands board, has been on overseas sabbatical for the past two months and has privately rejected speculation his departure from Mirvac is related to the tax matters. He could not be contacted last night. Mirvac declined to comment.