English translation has gone - Any idea how could this happen?

[ELEMENT MEDIA]

Hello guys, maybe you'll help me with this.
PrestaShop version: 1.6.1.19
Problem:

• All english translation from products are missing, they just gone in database.
• Missing categories translation, they gone like products translation.
• Theme / Frontend translation has been replaced by Polish translation.

The english language has been not deleted in backoffice [no logs that was removed].
Could CSV import done that? Employee has been updating products tags, categories assign with CSV import, but it didn't have any language settings.

Any idea how this could happen?

[ELEMENT MEDIA]

Problem solved. Employee has submit by mistake "copy translation" option in BO -> Translations.