Mr Pallotta, a millionaire born in the United States to southern Italian parents, promised to pay a fine for bathing in the Fontana dei Leoni in Piazza del Popolo, where he and a mass of fans celebrated the victory on Tuesday that sent Roma through to the Champions League semi-finals for the first time in over 30 years.

Fans cheered as the mogul did a backward somersault into the fountain, however not everybody was impressed with the stunt.

Consumer association Codacons complained to the city authorities over what it described as “a thoughtless and inappropriate act” on behalf of Mr Pallotta.

The group accused him of setting “a terrible example to millions of young people who follow football and Roma, and who should be taught to respect public patrimony and heritage,” stressing that bathing in Rome’s historic fountains is banned and carries a fine of up to €500.

Mr Pallotta called Rome Mayor Virginia Raggi on Wednesday to apologise for the act and said he would pay a price for his behaviour. 

“Pallotta said sorry, he did it in a moment of excitement,” Ms Raggi said.

“He understands the example he has to give, and he'll pay the fine.”

Mr Pallotta has also offered to donate €230,000 towards the restoration of another fountain, the Fontana del Pantheon, located in front of the capital’s ancient temple in Piazza della Rotonda.