High tide: Billionaire Lindsay Fox's seaside estate at Portsea, Victoria. Photo: Luis Enrique Ascui
The Victorian land titles office granted the extra beach land at Portsea to Mr Fox on Christmas Eve.
The move has angered the Victorian government, which is now considering court action against Mr Fox, legislative reform or a planning mechanism to ensure other landowners with similar titles cannot claim public beach space.
Mr Guy, who said he became aware of the titles office's decision only after his environment minister raised it with him, said the office had ''questions to answer'' and both ministers had issued a ''please explain'' to the agency. He said he was yet to see the advice the agency relied on and the government would now have to clarify the official location of the high-water mark across the whole state.
The extension of Mr Fox's title added 37 per cent more land - or 2400 square metres - to the two main Fox properties on the exclusive Portsea clifftop, extending the boundary past their house-sized boatshed and over the beach by 47.26 metres and 44.40 metres. The billionaire paid a $477.80 application fee for land worth $5.4 million based on recent sales.
Mr Fox has argued for 17 years that the property line of his $20 million family compound extended across the Point King beach to the margin of Port Phillip Bay. What constitutes the bay's margin has been a murky issue. Previous governments rejected Mr Fox's position.
Documents from the land titles office show that on Christmas Eve officials finally accepted the ''doctrine of accretion'' in relation to Mr Fox's property. This old legal principle means that when sand builds up on a beach - as it has at Point King - landowners whose properties abut a coastline can apply to have their title extended as the high-water mark recedes.
Mr Fox's new title goes to the mean high water mark of August to September 2009, as surveyed by the businessman's coastal engineer. It appears the titles office did not independently verify the evidence of the engineer or Mr Fox's surveyor before approving the extension.
Mr Guy said the Fox precedent would only affect those landowners with older titles abutting the coastline.
On Saturday one of Mr Fox's neighbours, Marita McIntosh, said she supported a title extension and that land titles adjoining Point King Beach clearly stated that a property line should begin at high-water mark.
Mr Fox's long-time nemesis, local activist Kate Baillieu, said: ''Poor old Lindsay, he hasn't got enough. It reminds me of a greedy child who grabs something, wraps their arms around it, stamps his foot and shouts MINE!''
Mr Fox was unavailable for comment on Saturday. Fairfax Media understands that he based his application on three precedents in Victoria in which coastal property owners have been given title extensions to the high-water mark.
with Henrietta Cook, Royce Millar