Sussex could have to pay a tax bill of nearly £5million on the windfall they received from the estate of former president Spen Cama.

The Inland Revenue's Capital Taxes Office have begun an investigation into whether they can claw back a slice of the £12million legacy in corporation tax.

Sussex have been promised a decision in the next two or three weeks.

Chairman David Green has admitted losing that amount would mean their plans to redevelop the County Ground would have to be drastically scaled down The legacy was bequethed to the county when Cama, who had no dependents, died in 2001 at the age of 92 and left an estate worth £30million.

Green said: "There have already been two separate investigations into the Spen Cama estate and we have been advised that the legacy is not subject to inheritance tax.

"But we could be liable to corporation tax which is why we have put any development plans on hold for the moment."

Sussex were due to start work on the southern end of the County Ground this month.

They plan to demolish the delapidated Gilligan Stand and replace it with a public pavilion and improved conference and corporate hospitality facilities to increase revenue streams on non-cricket days. There would also new spectator seating in the south-east and south-west corners of the ground.

Long-term plans to build flats and a hotel on the site of the Sussex Cricketer pub at the entrance to the ground are already on hold because of continuing uncertainty in the property and financial markets.

The club's committee are meeting on Wednesday to discuss the latest developments.

Green added: "Potentially it could be a disaster to our plans to develop the ground but our tax advisers have told us they don't think we will be liable. We are confident we are not going to get whacked."

Cama also left £7million to Preston Nomads CC but they protected their inheritance by creating a charitable trust for their windfall.

Ironically, the interest from the windfall means Sussex will announce a trading surplus at their AGM on March 31 of £215,884 despite an operating deficit of just over £303,000.

If Sussex do have to pay it could re-open the debate over whether they should leave Hove and move to a purpose-built site elsewhere in the county.

Meanwhile, Sussex are unlikely to know until next week whether they will have Mushtaq Ahmed in their side this season.

The 37-year-old leg-spinner is in Hyderabad preparing to make his debut in the breakaway Indian Cricket League on Sunday for the Lahore Badshahs.

If he plays, the Pakistan Cricket Board are threatening to withdraw the permission they gave Mushtaq to return to Sussex for a sixth season because they, like every other governing body in world cricket, do not recognise the ICL as an official competition.

One option open to Mushtaq is to try to break his one-year contract with the ICL but he may decide against that because of the legal costs involved. Former Pakistan team-mate Yousuf Youhana is being sued by the ICL after terminating his contract.

Coach Mark Robinson said: "We are really in limbo and waiting until Mushtaq plays to see what develops."

Andrew Flintoff will play against Sussex in the annual curtain-raiser to the new season between the champions and MCC at Lord's on April 11.