Variables Issue

Hey guys, I have one issue when it comes to variables. One of our colleagues has copied some of the elements from another design system and now we got their variables and we can not remove them. P.S. The components that were imported were immediately removed, but the variables seems to be left inside the Figma.

We use only this type of variables, but if I go to the developer mode in the playground, I will get this result

Does anyone know where they come from and how to get rid of them?

Thank you in advance 🙂