Anxious, Depressed and lost bc of my friend and his controlling and manipulative gf

My best friend a 28 years old guy has been manipulated by his 21 year old girlfriend. She made him block me, ghost me, and leave all social media, i cant reach out to him . She harasses me with childish messages, and she forces him to send her screenshots of any messages he receives, acting like his "owner." My friends and I are deeply concerned and hurt, as he's been my huge supporter through depression and anxiety. We're desperate to talk to him, not her, but she constantly interferes.

We live in different countries btw and i wanna talk to him but i CAN'T talk to him, he blocked me and idk how or who can help me i've been trying to look for his family or his roommates online but all i know is his roommate first name. I miss him so bad and just wanted my friend back that's all :(