Guitarist Matt Roberts, formerly of American rock band 3 Doors Down, has died aged 38.

While his cause of death remains unclear, it is believed he died of an overdose.

Roberts's father Darrell told TMZ that the reputed overdose was connected to prescription medication, and suggested his death was accidental.

Roberts, who left 3 Doors Down in 2012 citing health concerns, had been rehearsing on Saturday for a forthcoming charity gig.

Around 9am on Saturday morning, his father was informed Roberts had died during the night.

Roberts was one of the three founding members of 3 Doors Down, alongside Brad Arnold and Todd Harrell. After acquiring Chris Henderson as guitarist, they released a now multi-platinum debut album called The Better Life, known for such singles as Kryptonite and Duck And Run.

Upon his departure from the band in 2012, Roberts wrote: "3 Doors Down will always have a special place in my heart and it saddens me to take this time off, but my health has to be my first priority".