The lease on Kingston island Ravens Ait has been sold to a Middle East-based businessman for a seven figure sum, the Surrey Comet understands.

Stewart Marine Ravens Ait, the company run by former Olympic sailing medallist Ossie Stewart and which holds the lease to the island, has been sold in a deal rumoured to be worth £1.9m.

Mr Stewart was handed a 50-year lease three years ago by Kingston Council, promising to open a sailing school and water sports centre.

But the plan failed to materialise after it was deemed uneconomical, and the company instead re-opened Ravens Ait as a wedding and conference venue a year later after a £1m investment.

Former Conservative council leader Kevin Davis said: "It appears the council has given away one of its prime assets, and a businessman has potentially made a very large sum of money out of it.”

A spokesman for Kingston Council, which still owns the freehold, initially said the sale of the company was "news to us.”

But Kingston Council leader Liz Green said: “The council is aware that there has been some changes, and we are investigating as to what the implications are."

Mr Stewart, who is understood to be sailing, was not available for comment.

Squatter leader Peter Phoenix, 42, who took over the island in the summer of 2009 after the previous leasees went bankrupt said today: “If the new owners want to involve us we’d be happy to do something."

Companies House documents dated August 28 reveal leaseholder Stewart Marine Ravens Ait Ltd has appointed Marshal Gaspar, an Indian national living in the United Arab Emirates, as new commercial director.

Papers dated September 2 also reveal the company has changed its business address to an accountancy firm in Buckinghamshire.

Bucks-based solicitor Lennons confirmed it was representing Mr Gaspar, but declined to comment further.

As part of the lease the island must be allowed for 10 days of community use, including use by the sea scouts.

1st Surbiton Sea Scouts president Roger Jones said: “As far as we know, the sea scouts have been here for 25 years and I cannot see any reason why we can’t be allowed to continue.”

The decision by the ruling Liberal Democrat party to lease the island to Mr Stewart was ‘called in’ by opposition Conservative councillors who held a scrutiny meeting behind closed doors in March 2011.

Attendees included council leader Derek Osbourne, Conservative leader Howard Jones and the borough valuer.

But the sections relating to the value of the island were kept confidential for commercial reasons.

At the time Coun Jones said: “There were offers on the table from people who were willing to pay four times what Stewart Marine offered.

"That four times, in our view, could well have been a very good deal, but whether it was followed up sufficiently is something I cannot discuss fully."

A move to sell to Antoinette Hotels, based in Surbiton, had fallen through.

The island is believed to be the setting for the Treaty of Kingston in 1217.

Press baron Robert Maxwell was rumoured to have wanted to buy the island and put a casino and helipad on it.

Kingston Council bought the site in 1989.