The parents of a student nurse who went missing in Germany 10 months ago have employed a retired police officer from north Wales to try to speed up the inquiry.

Louise Kerton disappeared last July on her way back to the UK after a visit to her boyfriend's family in Germany.

Lucie Blackman was a friend of Louise

Her disappearance - days after she learnt she had failed her final nursing exams - followed the high profile case of Lucie Blackman, the former air hostess found raped and murdered in Japan.

Louise Kerton and Lucie Blackman were friends and had attended the same private school in the south of England.

Despite intensive searches, no trace of the 24-year-old has been found.

In Tuesday's Week In Week Out programme on BBC Wales, a German police officer reveals that he believes Ms Kerton is probably dead.

Her parents now live in Kent, but her mother Kathy is originally from Holywell in Flintshire, and her father Philip from Abergavenny in south Wales.

The couple have spent their life savings looking for her and relatives from all over Wales have joined searches in Belgium and Germany.

Speed up

Despite the suspicious circumstances, the case has failed to progress because German police are often reluctant to investigate missing person inquiries.

In the Week In Week Out programme, two Swansea-based language experts analyse Ms Kerton's last letter home and claim to uncover significant new evidence.

Philip Kerton wants more questions to be asked

The programme also describes how the Kerton family have employed Caernarfon-born Dai Davies, a retired police officer, to try to speed things up.

Ms Kerton, from Broadstairs in Kent, who had been staying with her fianc� and his mother in Germany went missing after arriving at Aachen station.

From there she had been due to travel to the Belgian port of Ostend and on to Dover - but never arrived.

Human rights

Earlier this year, a team of detectives from Kent travelled to Germany to try to persuade the authorities to start a fresh search.

Her father, who has been very critical of the investigation, has said German police were not doing enough to find his daughter.

Mr Kerton said part of the problem was the attitude of the German state towards missing persons.

He said the state regarded searching for missing people as an infringement of their human rights unless they were ill or depressed when they went missing.

Week In Week Out can be seen on BBC One Wales at 2235 BST on Tuesday.