How do you find out who deleted a branch?

[Philip Wilder]

Details

Weird problem.

• For a particular repo we use environment branches (particulars of why shouldn't be relevant to this question). These branches are designed to be long lived.
• Recently one of these branches (say FOO) disappeared. It was assumed at the time that someone accidentally closed the branch when merging to master. So we update the branch permissions in repo settings so deletion of the branch is not allowed.
• Since that update the branch has disappeared 2 more times.

It's remotely possible that someone with admin access is removing the delete restriction, deleting the branch and turning the restriction back on although this would be strange, the dev team is small and AFAIK we are rowing in the same direction. 

Question 

Is there a way I can determine who / what deleted a branch and ideally how? Thanks.

[Philip Wilder]

This is probably the most complete answer to the question: https://community.atlassian.com/t5/Bitbucket-questions/is-it-possible-to-know-who-deleted-the-feature-branch-and-when/qaq-p/950826#M35947