A Hunstanton-based charity sparked into action at the weekend after fears were raised staff at a hospital in Mexico would switch off a British girl's life-support machine because a crucial cash transfer was delayed.

Little Olivia Downie, who suffers from the aggressive form of childhood cancer Neuroblastoma, was flown to Mexico last month for innovative treatment which is not available on the NHS.

But the last-ditch treatment to save the seven-year-old's life failed and Olivia was put on a ventilator last week after one of her lungs collapsed.

Familes Against Neuroblastoma, based on the West Norfolk coast, funded the treatment at Hospital Angeles and is currently raising money to fund her current medical costs and to fly her home to die.

But the RBS/NatWest bank meltdown last week stopped a cash transfer from the charity to the Mexican hospital and Olivia's parents Steven and Lauren claim they were told their daughter's ventilator would be switched off if a bill was not paid this week.

They then contacted Linza Corp, founder of the charity, who put in frantic calls to NatWest, where the charity's account is held, Downing Street and the British Embassy in Mexico.

Ms Corp said: 'Olivia's mum was quite hysterical when she called us on Friday. She told me nurses came in and tried to take them into a side room so that they could terminate her life-support.

'I checked our online banking service but I couldn't see if any of the funds had gone out and couldn't do anything. I then tried to get through to our telephone banking service but couldn't so we were pretty desperate.

'As we didn't know how long we had, I put in calls to Downing Street, the police here and the British Embassy over in Mexico.

'Eventually I got hold of somebody at NatWest, who acted quickly and made sure that money was sent to America to then be sent to Mexico, so everything is going to be OK.'

Officials at Hospital Angeles have denied that the threat had been made but confirmed that the family were behind in their payments - believed to be in the region of �3,500.

Olivia, from Scotland, was diagnosed with stage four neuroblastoma three years ago. Doctors found a tumour the size of a grapefruit beside her kidney and she was given only a one in five chance of survival.

The family have previously flown to Germany so she could receive immunotherapy and went to the Hope 4 Cancer Institute in Mexico to try photodynamic therapy which her parents hoped would saver her life.

Last night, the fighting fund for Olivia had reached �150,000 - enough to pay for an air ambulance to bring Olivia home.

Ms Corp added: 'It is hell on earth for them over in Mexico. We are ready to bring her home now but she has not been able to fly home. We are waiting for her to stabilise and then we will fly her back.'

Linza Corp started the charity in June 2009 after her son Max lost his battle with the cancer. He was just 17 months old and was due to fly to the US for life-saving treatment.

The charity helps other parents generate funding for the treatment her son was unable to receive.

Donations can be made at www.justgiving.com/olivia-downie-appeal