a tech-related inquiry

It’s not strictly software development, but I figured you folks might be able to assist. I manage a Munch group. About three years back, when I first became the Organiser, there was a dedicated website or web pages for us. They gave me access and the password so I could make updates myself. Later on, though, the person who originally founded the Munch moved away and basically vanished without leaving any details. After that, I lost my ability to log in. The tricky part is that search results still bring up those old Munch pages via Google, even though they are completely outdated and confusing. I’ve sent emails to the contact address listed but keep getting bounced back. Does anyone have suggestions on how I can discover who currently owns the site, remove it, or perhaps regain access? Thanks