Hello George,
Using the API explorer, it is not possible to reproduce the issue here. All translations from English into Italian resulting in a text containing “rilascio” do not show any extra characters.
It might prove helpful if you provide us with the exact English text you translated, or similar edited text, if confidential.
Did you use the API explorer as well? How does your app access the translation API service?
All related information, that you deem relevant, may help us in reproducing the issue.