The size of our repository suddenly increased to 10Gb

Hi, we have repo: https://bitbucket.org/deskalertsdevelopment/deskalertsserver

And it now displays this message: This repository's size is over 10.6 GB. Read more on how to reduce the size of your repository.

But:

E:\Tmp\DA>git clone --mirror https://fzakharov@bitbucket.org/deskalertsdevelopment/deskalertsserver.git\\
Cloning into bare repository 'deskalertsserver.git'...
remote: Counting objects: 64522, done.
remote: Total 64522 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (64522/64522), 1.51 GiB | 1.92 MiB/s, done.
Resolving deltas: 100% (47591/47591), done.