'My children are priceless': Nigerian woman, 43, admits she can't pay £500,000 NHS bill after giving birth to IVF quadruplets as the cost of health service tourism at just one hospital is laid bare

A Nigerian woman who gave birth to IVF triplets after a stop-over flight to the UK will detail her journey in BBC2 documentary Hospital, tomorrow. The 43 year-old Lagos native, known as Priscilla (left), was filmed over several weeks at London's St Mary's Hospital while racking-up a £500,000 bill which remains unpaid. Her case exposes the crippling costs that health tourists place on taxpayers, with Whitehall research putting the cost to the NHS at anywhere between £200million and £2billion a year. Other examples include a Palestinian man who 'disappeared into the community' following a kidney stones procedure (bottom right) and a Filipino woman (top right) who had heart surgery after falling ill visiting the UK, only to return home unable to pay for the procedure.