Italian officials on Monday hailed the capture of a mob boss who was a fugitive for 23 years.

Rocco Morabito, whom the Interior Ministry described as "the number one wanted member of the 'Ndrangheta (mafia)", was discovered under an assumed identity at the weekend in the South American country of Uruguay after a months-long joint investigation by Italian and Uruguayan police.

"Arrested in Uruguay Rocco Morabito, a 'Ndrangheta associate, in the list of the most wanted fugitives... on the run for 23 years," Italian State Police tweeted on Monday afternoon along with a photo of a the grey-haired, overweight mobster, who is reportedly in his early 50s.

"State action against organized crime achieved another significant result with the arrest of... Rocco Morabito, wanted internationally since 1994 and on the list of most dangerous fugitives," the Italian Interior Ministry said in a statement issued Monday.

The ministry credited "the excellent international investigative cooperation between Uruguayan Police and the Italian Department for Public Security" for the arrest.

The "king of cocaine", as Morabito has been dubbed by some Italian and international media, faces 30 years in prison in his homeland following a 1994 conviction for mafia-style criminal association and international drug trafficking.

"The arrest of 'Ndrangheta boss Rocco Morabito is splendid news," tweeted Senate Speaker Pietro Grasso, a former anti-mafia magistrate. "Our compliments to the Italian and Uruguayan investigators," Grasso tweeted.

The Interior Ministry statement said Morabito was arrested in the luxury beach resort of Punta del Este, while a (Italian armed police) Carabinieri colonel said in a televised statement that the fugitive was nabbed in a hotel in the Uruguayan capital, Montevideo.

The 'Ndrangheta is a powerful organized crime syndicate based in the Calabria region in the tip of Italy's boot.