An Italian beautician has hired a private detective and taken DNA tests to prove she is the secret granddaughter of the founder of the Lamborghini sports cars empire.

Flavia Borzone, 35, from Naples, got a private detective to snaffle a straw from Elettra Lamborghini, who is a model, socialite and singer, to obtain her saliva and prove they are sisters. Flavia is convinced she is the illegitimate daughter of 76-year-old Tonino Lamborghini, whose father Ferruccio created the luxury car in northern Italy in 1963.

The claims have now emerged as they have made it as far as a court case in Bologna in a bitter defamation battle. Flavia is being sued by the son of the founder for defamation after she publicly claimed he slept with her mother and was her real father.

Flavia says Tonino Lamborghini, the son of Ferruccio Lamborghini, met her mother, Neapolitan opera singer Rosalba Colosimo, in the late 1980s when she was 17. She said Lamborghini stopped and offered a ride to Rosalba as she waited for a bus in Milan. The pair allegedly struck up a relationship, and in 1988 Flavia was born, it is claimed.

Experts from the University of Ferrara said that the DNA sample proved a genetic match between Flavia and Elettra, showing they were sisters. Lawyers for the beautician said the DNA link was "irrefutable" and one Italian newspaper said the alleged DNA-laden straw had "a thousand secrets." Flavia told the court: "I don’t want to offend anyone, I just want to know whose daughter I am."

Her lawyer Gian Maria Romanello said: "She had had this niggle for a long time. She did not have the same physical features as her supposed father. When he and her mother argued, she would often hear her mother say: 'She’s not even your daughter.'" The beautician covertly recorded the conversation she had with Mr Lamborghini and it was presented in court, according to La Repubblica newspaper.

Flavia Borzone, 35, is being sued by the son of the founder of the legendary hyper-car manufacturer (
Image:
Instagram)

"In the conversation, Mr Lamborghini admitted to having had a relationship with Colossimo [Ms Borzone’s mother]", the lawyer told the court. "They met in 1980 in Milan. Rosalba was waiting for a bus, Tonino passed by in his car, he gave her a lift."

Flavia's mother said: "My daughter doesn’t want money, she just wants the truth. If it had been all about the money, I would have done all this when Flavia was two years old." Mr Lamborghini has denied having any biological link to Ms Borzone. His lawyers said the DNA material was taken from the straw used by his daughter without her consent. It was therefore "unlawful" and should not be admitted as evidence.

Flavia's legal team said Mr Lamborghini had refused to undergo a DNA test, which is why they hired four private detectives to obtain the drinking straw used by his daughter. The legal team told the court: "Our client and Elettra Lamborghini are sisters. They are daughters of the same father. This should be enough to throw out the accusation of defamation because [Ms Borzone and her mother] have just told the truth."

The company, which also has interests in hotels and resorts, is worth around €400 million (£341m), according to Italian media reports. The trial was adjourned until March.