The 17-year-old was taken to hospital but she could not be revived and medics are investigating the possibility that she suffered a rare allergic reaction to the hydrogen peroxide in the colourant.

Her friend, Heather Goodhall, said she and Tabatha had been enjoying a ‘girlie’ night in watching The X Factor before tragedy struck on Saturday.

She added: ‘The dye had only been in around 20 minutes when she got up and went to the bathroom. She came back a couple of minutes later, sat down on the seat, and then began frantically pulling the foils from her hair.

‘She started shouting, “No, no”. It was really scary. Then she fitted and went limp, like a rag doll.’ The 17-year-old said her best friend was ‘hyper and bubbly’ and was ‘always dyeing her hair different colours’.

Tabatha lived with her parents, Margaret and Peter, and sisters Tiffany, 15 and Jasmine, 11, in Airdrie, Lanarkshire. Her mother asked that the family be left to grieve.

Jasmine posted on Facebook: ‘RIP big sister. I know you are gone but you will  always be in my heart. Love you so much xx.’

Tabatha's death has been recorded as ‘unexplained’ and police have begun an investigation.