Remove ssh key from account by ssh

Somebody add my public key to his account. And I can't use it in my account.

I try to do ssh -T git@bitbucket.org and see account, what I doesn't know.

As workaround I create temp-key for bitbucket only. But it is non comfortable to use one key for all and other for bitbucket.

I want to remove my public key from account.

For example with command:
ssh -T remove-my-key@bitbucket.org

Then owner of private will remove own key from any any account.