The nanny of John Travolta and Kelly Preston's late teenage son is to be quizzed by police.

Jeff Kathrein is to be questioned after it emerged he has no formal childcare qualifications and earns a living as a wedding photographer.

It has also been claimed that although he was employed as 16-year-old Jett's primary care-giver he was never actually referred to as the boy?s nanny until after his tragic death.

A source explained to the MailOnline website: "Jeff has known John for years. I think they met through Scientology. Jeff always travels with John and then when Jeff met his wife Ana, she started travelling with John and Kelly too. But I never heard Jeff referred to as a nanny until Jett's death."

Although police have confirmed the cause of Jett's death — who died after suffering a seizure while on holiday with his family in the Bahamas on 2 January — is not being disputed, they are still keen to probe the case and it remains open.

Kathrein was the last person to see the teenager alive, and is believed to have helped John perform CPR on the boy when he was discovered in the bathroom.

Checks on national databases have confirmed Jeff does not have any professional childcare qualifications.

Jett suffered from Kawasaki disease, a rare circulatory condition which usually only affects toddlers and is not considered fatal.

He needed constant care, with Travolta and Preston employing two carers to give him round-the-clock assistance.

Kathrein and a man called Eli shared a ground floor suite linked to Jett's room while the family were on holiday, but police are said to be investigating claims Jett was left on his own for up to 10 hours while the nannies watched TV.