Darius Campbell was left in a coma, fighting for his life, after drinking dirty water from the Thames.

The 37-year-old singer-and-actor - who rose to fame on reality shows 'Popstars' and 'Pop Idol' - was filming a promotional video for a water aid charity when he unknowingly drank from a bottle that had not been filtered.

Darius, who has now made a full recovery, told The Daily Record newspaper: ''I drank the water for the video and raised the funds but, when I went to Glasgow to see my mum for her birthday, I collapsed. It turned out I had a cerebral oedema where your brain swells bigger than your skull. Dad saved my life. He got me to hospital. They diagnosed it quickly.''

The former 'Popstar to Operastar' contestant had contracted an inflammatory virus from drinking the water taken from next to sewage outlet on the Thames, leading to bacterial meningitis.

Darius' mother Avril was having chemo and radiotherapy for breast cancer at the time her son collapsed in 2015.

The West End star revealed: ''As I came out of the coma, I remember my mum sitting beside the bed.

''It felt upside down and wrong because my mum was going through cancer treatment.

''Yet she was next to me with tears in her eyes telling my brother that they almost lost me.''

Darius is a founding ambassador of non-profit organisation Fresh2o along with actress Keira Knightley and Formula One racing driver Lewis Hamilton. The charity was set up to dig wells in Africa using profits from portable water filters.

Following his illness he feared the filter he had been promoting in the demo video - which removes 99.9 per cent of known water-borne pathogens, bacteria and viruses - was faulty. But it emerged that Darius had been given a bottle without a filter.

He said: ''I suddenly got a shock, worrying that the water filters didn't work and that they had been sent off and that other people could have died from this.

''But other people who drank the water didn't get sick and it was a huge relief when we found out the water filter I used was a display model without a filter.

''So, in an inadvertent way, I proved the water filter worked because the others who drank from a bottle with a filter in it, didn't get sick.''

Darius was left bed-bound for three months while he recovered from the disease.