A 14-year-old boy who dyed his hair brown after being teased for his red hair was found hanged in his bedroom.
Simon Walters was discovered by his dad Nigel, 42, at their home in the West Midlands.
At the inquest into his son's death, Mr Walters said his son had been bullied at Heath Park School in Wolverhampton for more than five months and had complained to teachers.
However, both police and the head teacher told the hearing that there was no evidence of bullying at the school.
Mr Walters said: "In May last year I noticed a lump on his head. When I confronted him about it he said a boy at school hit him.
"On another occasion when I called Simon to tell him I would pick him up from school I heard children calling him names in the background.
"I discussed the matter with the school and was told there was a zero tolerance policy towards bullying."
Mr Walters, who lived alone with his son, said he was reassured the matter would be resolved but the next day Simon begged his father to go to school with him.
"He was terrified, he was shaking, he was crying. I asked if everything was okay afterwards and he said it was sorted," said Mr Walters.
"He was very withdrawn towards the end. It actually got me very upset and I would cry in front of him asking him: 'What is wrong - I know you have changed?' He used to be a jolly lad, he enjoyed telling jokes, he was a pleasant little boy and was well behaved.
"I was really concerned, he just used to always speak to me but then he stopped talking to me, he used to shut himself in his room. My own conclusion was that he was being threatened not to say anything."
Mr Walters described the moment he found his son dead after returning home from a night shift at 4.15am on a day in October last year.
He said: "Simon's music was blaring and his lights were still on so I went upstairs to tell him to go to bed. He was hanging. I just ran downstairs screaming - I could not believe it. I was in shock."
A police investigation also found Simon had been teased because of his ginger hair and had researched how to commit suicide on the internet.
But Detective Inspector Richard Scott, from West Midlands Police, said there was not enough evidence that he had been bullied by his peers.
He said: "His school friends have told us there was teasing because he had red hair. That was what one of his friends said - that there was teasing because he had dyed his hair."
Heath Park School head teacher Georgetta Holloway also told the hearing there was no evidence of bullying at the school.
She said: "No one had seen a change, nothing was reported to his friends other than the incident in May described. He was a popular young man but very much a young man, he was a joker. He had a wide circle of friends."
Recording a verdict of suicide, Black Country Coroner Robin Balmain said: "The only possible motive that comes to light is bullying. However, I have to say there is no clear evidence.
"The police have carried out a clear investigation and we have heard evidence from Mrs Holloway.
"Perhaps most importantly the police have been able to read his Facebook record and there is nothing that suggests he was being bullied. This is a tragedy for the family and also for Simon's friends."