It sounds like a grizzly dispute from a Spanish version of the Jeremy Kyle show, but this battle has some more serious weight – and money – behind it.

The remains of the man they nicknamed 'Franco's banker', millionaire Juan March, have been disinterred in a bid to clarify claims by a 65-year-old retired woman from Valencia, Ana María Gallart, to be his illegitimate daughter.

In a complex four-hour operation, a three-and-a-half ton slab of stone was slid aside from Mr March's heavily ornate neo-classical mausoleum in a cemetery in Palma, Mallorca, on Thursday. His body, still in its coffin, was then removed for DNA testing ordered by a Madrid judge.

Should the woman's claim be upheld, media reports claim she will receive up to 200m euros as part of her inheritance from Mr March's estate.

Gallart, whose mother was in domestic service to the March family, says she is no opportunist. “If I had wanted the money, I would have claimed it decades ago, I just want to know who my father is,” she told the El Mundo newspaper.

Mr March was a key financial backer of General Franco's rebellion in July 1936. He also hired Dragon Rapide, the plane which flew Franco to Spanish territories in northern Africa to initiate the uprising. He died in 1962 in a car-crash, and Gallart only discovered her alleged connection to Mr March when she came across a folder entitled 'Anita's documents' belonging to her adopted parents. “As a Christian, exhumation is abhorrent to me and I ask Juan March's forgiveness every day,” she said. “But I have no choice.”