What was the "Siluro a Lenta Corsa"
and who was credited with creating it ?

It was an Italian midget submarine.
The Italian submersible Siluro a Lenta Corsa, translated as "slow running torpedo", was used during World War II for commando operations. To maintain secrecy, the submersible was developed at a remote farm site, and was nicknamed Maiale ("pig"). It had electric propulsion and joystick steering. Launched from a larger submarine, it’s two-man crew in scuba gear maneuvered from the open cockpit. Once near the target ship, they would attach explosives with a timed fuse. Despite their small size, these all-battery-propelled Siluro A Lenta Corsas achieved effective results early in the war against British ships at Gibraltar, Spain and Alexandria, Egypt.

Quite right.

Thanks for the answer Jenny !