I have a guy in my team who hasn't produced anything meaningful. 3 months ago I told my manager and the product owner that I can not include him into our sprint

I have a guy in my team who hasn't produced anything meaningful. 3 months ago I told my manager and the product owner that I can not include him into our sprint plans since he can not deliver anything. He still shows up in the scrums and tells us he is "working on errors". No one has any clue what he is supposedly doing. We wish our manager would just fire him. Currently our suspicion is that he is related to some higher up.