A lecturer is suing his former wife for £100000 (R1.83-million), claiming she deceived him into thinking he was the father of a boy born after fertility treatment.
The British man, who is in his 60s, claims he only found out that the child had been created with sperm provided by his wife's former boyfriend when the boy was five.
The boy is now nine and the couple divorced in 2008. The woman - who at one stage earned more than £180000 a year - says there is "no merit" in the damages claim, which is believed to be the first case of its kind. She said she thought the man knew he was "not necessarily" the father.
Judge Deborah Taylor banned publication of anything that could identify the boy.
The court heard that the couple married in 2002 and travelled in 2004 to a clinic in Barcelona, Spain, for IVF treatment, where the man gave a sample of his sperm.
A few months later the woman, now in her 50s, returned to the clinic with a former boyfriend and was impregnated with his sperm.
Lawyer Thomas Brudenell, for the lecturer, said the man looked after the child and paid more than £80000 in maintenance over a few years.
The man claimed damages for "distress and humiliation", maintenance and compensation for loss of earnings.
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