But Dati, currently a member of the European Parliament, denied the claim, telling AFP: "It's false."
The Lucien Barriere group, which Desseigne heads, made a statement through its spokesman saying Dati had made a legal bid for "recognition of paternity" for her daughter Zora, born on January 2nd, 2009.
Dati had kept the identity of the father a secret, sparking a French guessing game that prompted Spain's former prime minister Jose Maria Aznar to formally deny paternity in a bid to squash rumours.
The others who figured in the frenzied speculation included a top Qatari official, a prominent French TV host, a leading Paris businessman and Desseigne.
Desseigne's chain, which includes 37 casinos, 15 luxury hotels and nearly 130 restaurants and bars including the famed Parisian restaurant Fouquet, posted turnover of nearly €1.1 billion ($1.4 billion) last year.