Mysterious Data Deleted from Standard Tables

In our system data from standard table has got deleted the tables are COSP etc. Wanted to know is there a way we can find when the data was deleted and who/which interface deleted it ? As we have identified the data to be missing now , Don't know when in the last 2-3 days the data could have been deleted. Any thoughts or steps where I need to look out for.

Rgds,

Ankur Bhandari