World champion high jumper Gianmarco Tamberi, Italy's Olympics flag bearer, had some making up to do on Saturday after the Italian lost his wedding ring in the Seine river during the opening ceremony of the Paris Olympics.

The ring slipped off Tamberi's finger as he enthusiastically waved the Italian tricolour during the boat parade in the Parisian rain on Friday.

"I'm sorry, my love, I'm so sorry," the charismatic 32-year-old wrote on Instagram in a post dedicated to his wife, Chiara Bontempi Tamberi.

The high jumper blamed "too much water, too many kilos lost in the last few months or maybe the irrepressible enthusiasm of what we were doing. Probably all three".

Tamberi famously shared Olympic gold in Tokyo three years ago with Qatari friend and rival Mutaz Barshim.

The Italian has a reputation as something of a showman, including leaving one half of his face unshaved.