Great Britain Basketball [GBB] officials fear that the insurance problems that are preventing Luol Deng, the Chicago Bulls forward, from playing for his country will rule him out of the 2012 Olympic Games in London and even put Britain's involvement in the tournament in doubt.

The sport's governing body has seven days to find $500,000 (about £272,000) for an additional insurance premium if Deng, who is an ambassador for London 2012, is to take his place in the qualifying campaign for next year's European Championship A division finals, starting against Israel in Tel Aviv a week today.

The root of the problem lies with MetLife, the NBA's insurer, which covers the top 150 salaries in the American league on a group policy. Under the terms of its agreement with the NBA, MetLife has the right to exclude 14 high-risk players every year, a decision based on the individual's injury history and the amount of money remaining on his contract.

Deng came under the company's spotlight when he signed a new $71million, six-year contract at the start of this month, the fourth-highest contract in the league at present in terms of outstanding money. MetLife subsequently used an MRI scan taken last November when Deng, 23, injured his back and missed three games to exclude him from the coverage.

Exhaustive work has produced a quotation of $500,000 for supplementary cover and GBB officials are working on the assumption that they will have to unearth a similar fee every summer between now and the London Olympics to allow Deng to play - a total cost of $2.5million for a programme that runs on an annual budget of about £1.5million.

“This is a devastating blow,” Chris Spice, the GBB performance director, said. “If Luol doesn't participate this season or any other season leading up to London, there is no question our involvement is in doubt. The world governing body [Fiba] has not been very specific, but we know from discussions that we need to be playing in the A division tournament in Europe to be given a place in the Olympics.

“If we fall out of the A division next year and cannot participate in the A division for [the 2011 European Championships], there is a real possibility we will not play in London.”