An oil technology millionaire has been ordered to increase his former wife's divorce settlement from £5m to £8m.
Victoria Jones, 44, claimed at the Court of Appeal that she got just 20 per cent of the 25m marriage assets from her former husband Gareth Jones, and wanted 10m.
Mr Jones, 58, who has retired to his 16th-century castle in Scotland, said the settlement was fair following a "troubled" 10-year marriage.
But three judges at the Court of Appeal, in a ruling critical of the High Court divorce hearing, found that the value of the assets generated during the marriage was 16m and she should have half.
Lord Justice Wilson said High Court judge Mr Justice Charles's ruling was "too unwieldy".
He said it had "been a challenge" to work out why Mrs Jones was awarded 5m plus 400,000 towards her costs.
Sir Nicholas Wall, the president of the High Court Family Division, said it was "unfortunate" that the law was dictated by big money cases "which bear no resemblance to the ordinary lives of most divorcing couples".
He said the sums of money involved are beyond "the experience and even the contemplation of most people".
Lord Justice Wilson said Mr Jones was the sole owner of Dominion Technology Gases which he sold during the divorce settlement hearing in May 2007 for 32m, from which he received 25m.
But, said the appeal judge, he had "dishonestly suppressed the existence of the negotiations" and had told the court the value of the company was 3m.
Lord Justice Wilson ruled that 9m of the total assets belonged solely to Mr Jones because they were effectively generated before the marriage in 1996, leaving 16m to be shared.