Mr Kamprad still pulls the strings at Ikea, some say

Swedish business weekly Veckans Affarer announced that Ingvar Kamprad, founder of Ikea, had topped Mr Gates, with a 400bn-kroner (�29bn; $52bn) fortune.

The report was quickly taken up by media around the world.

But according to the furniture store, the magazine forgot that Mr Kamprad has not owned Ikea since 1982.

Veckans Affarer admits the anomaly, but insists that Mr Kamprad still calls the shots at the firm, and so can be considered its de facto owner.

'Completely wrong'

The dispute is one of methodology: Veckans Affarer has simply added up the total value of Ikea's 186 stores in 31 countries.

Ikea argues that this is flawed, since Mr Kamprad donated his interest in the firm to a Dutch-based foundation in 1982.

"This is completely wrong. It's a mistake that is made all the time," said Ikea spokeswoman Marianne Barner.

"Estimating the value of the company, including all the stores, and saying it's all Ingvar's, that is totally wrong."

Forbes, the US magazine which compiles what it claims is a definitive list of the world's wealthy, puts Mr Kamprad at number 13, with a fortune of $18.5bn.

Pulling the strings

Veckans Affarer has stoutly defended its position.

Its basic argument is that the Kamprad family still effectively own Ikea through a network of foundations.

Mr Kamprad has claimed that the foundation structure prevents him passing on the company to future generations, but the magazine disputes this.

Such structures are not unknown in Sweden, where top companies are keen to avoid high levels of taxation.

Mr Kamprad, whose three sons work in senior positions in the firm, has moved his personal headquarters to Switzerland to take advantage of its generous tax laws.