"Gianpaolo Ravazzotti and his colleagues tragically passed away in an aeroplane accident on Tuesday 08 February 2011," the company's board said in a statement released on Wednesday morning.
"The wreckage of the aircraft has been located in the Robberg area and the bodies of all of the passengers have been found.
"A full investigation is underway to determine the cause of the crash."
The dead include Ravazzotti and eight of his colleagues and business partners - Gia Celori of Italtile Ltd, Marilize Compion of Italtile Ltd, Sava Di Bella of Prima Bella Bathroom Accessories, Simon Hirschberg of the company Grainwave Pty Ltd, Jody Jansen van Rensburg of CTM Alberton, Aletsia Krause of Italtile Ltd, Bronwyn Parsons the pilot for Italtile Ltd and co-pilot Alison van Staden.
"On behalf of the board, I express my heartfelt sympathy and condolences to the chairman of the group, Mr Gianni Ravazzotti, his wife Annabel and their daughters and Gianpaolo's wife, Vanessa and their children, as well as the families of all of the deceased," Italtile chief financial officer Peter Swatton said.
"The group will ensure that every effort is made to provide the counselling and support required by those affected by this tragedy."
The board said it would announce its succession plans "in due course".
NSRI spokesperson Craig Lambinon told Sapa the aircraft's wreckage was found just off-shore of the Robberg Nature Reserve at 06:06 on Wednesday.
The aircraft had been travelling from Queenstown to Plettenberg Bay on Tuesday.
It disappeared at 16:00 on Tuesday while trying to land near the Robberg Nature Reserve in heavy fog.
The plane was believed to be a single-engine Pilatus PC-12.
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