Deleting video clips in the video browser

Hi,

Hope someone can help.

I have video clips in the video browser for imovie 2.1.1 on iphone 6.

-They are not in any project I have,

-They are not in my photo library under videos

I can not for the life of me work out how to delete them off my iphone without deleting imovie, but not sure even that will get rid of them.

I have searched and seems others have same problem but no way to remove. I do not have a mac and just use the app on my phone.