Gwent Police say the human feet found near the River Severn don't belong to Richey Edwards.
The trainers containing the human remains were first manufactured in 2001.
The Manic Street Preachers star went missing in February 1995.
The investigation is continuing, although Edwards has been eliminated from the inquiry.
Detective Sergeant Dave Edwards told NME.COM: "We recently spoke to Diadora and the trainers were manufactured and distributed in 2001.
"This has helped the enquiry enormously and we've been able to eliminate a number of missing persons, including Richey Edwards of the Manic Street Preachers."