Jamie Shaw claimed he had his arms bound to his side with a ball of wool and was then lashed to the chair after refusing to sit still. The boy kept his ordeal secret for weeks before plucking up courage to tell his parents.
His father, Stephen Shaw, said last night: 'We couldn't believe what we were hearing - it is barbaric.
'Jamie had been having nightmares and wetting the bed for weeks before he told us what was bothering him . . . I don't think this woman is fit enough to teach children if she can't control a child in any other way.'
Mr Shaw and his wife, Jayne, from Cwmbran in Gwent, have taken Jamie out of the town's Hollybush Junior and Infants School because of the incident.
A Gwent County Council spokesman said: 'This is a practice we would totally discourage any teacher from taking.'