If you have deleted a report from Live Reporting, we currently don’t have a trash to restore it from. However, when you create/edit a report it will be stored locally on the disk you are working on. To be able to restore the report, you must find the user who created/edited this report. Locally on his/her machine there is a copy of the file. Open another report on his/her computer → go to File → Info → Related Documents section:

Locate the file in this OSR folder and use the upload function within Live Reporting to import the file into the Portal again.