José María Ruiz-Mateos who founded the conglomerates Rumasa and Nueva Rumasa died on Monday aged 84 in hospital in Puerto de Santa María in Cádiz.
His funeral took place on Tuesday and his body was due to be cremated on Wednesday. But a judge at court number 2 in Pozuelo de Alarcón halted the cremation after agreeing to investigate a paternity claim, reported El Pais.
Adela Montesdeoca claims that she is the secret daughter of Ruiz-Mateos, who was married to Teresa Rivero with whom he had 13 children.
Ruiz-Mateos was a controversial character with a reputation for shady business dealings and was under investigation for fraud at the time of his death.
He was responsible for one of Spain's largest financial scandals, a pyramid scheme that almost unbalanced Spain's economy in the 1980s.
Facing charges for defrauding the taxman of 20 billion pesetas, his companies were seized in 1983 and he was tracked down hiding in London and extradited to Spain.
But he went on the run again, disguising himself in a raincoat and wig to evade police officers leading up to a court appearance.
He became one of Spain's richest men and bought Ruiz-Mateos the Madrid-based Rayo Vallecano football club.
In July he was sentenced to three years and nine months in prison but suffering from ill health he was instead taken to hospital where he died on Monday.