Matt Roberts has died at the age of 38.
The former 3 Doors Down guitarist passed away in a hotel in Wisconsin on Saturday (20.08.16) and the cause of death is not yet known.
His father Darrell Roberts, who was staying in the same hotel, told CNN: "I was wakened at 8:50 this morning by some detectives beating on my door. It's always scary as a parent, they were in suits and that's when they told me. They asked me if Matt Roberts was your son, I said yes, and they said, 'We have bad news to tell you, Matt deceased last night'."
A statement from West Bend police said they received a call to say that a man was "either asleep or passed out in the hallway of his hotel".
Darrell had last seen his son the night before, when they were going to sleep in adjoining rooms.
He said: "We go up to our room, we got adjoining rooms and - he was always looking after me as his dad - so my key didn't work and he went and came back in just a few minutes and got me a new key. He opened the door for me and he said 'just make sure you open the adjoining room in case you need anything.' He was always looking out for me."
The pair were in Wisconsin because Matt was due to play at a Rockin' for Heroes benefit.
Matt had struggled with an addiction to prescription medication but Darrell thought he had beaten it.
He said: "I know he had prescription drug addiction. He suffered greatly from anxiety. It's crazy as a performer; he never liked crowds or liked places he didn't know about as a baby, as a child, and this was his way of dealing with it and me and him talked about it often. I thought he had beaten it all."
Founding member Matt left 3 Doors Down in 2012 to concentrate on his health after becoming exhausted by the band's extensive touring schedule, which can include up to 300 gigs a year.