Sky News has learnt the authorities in France are not pursuing the maths teacher who ran off with schoolgirl Megan Stammers as a criminal suspect.
Citing a senior French prosecutor, Sky News Crime Correspondent Martin Brunt said as far as French authorities were concerned the matter is a missing person inquiry, not a criminal investigation.
"It means that there are no credit card checks, no mobile phone checks being made – the sort of things that police would normally do in a criminal case, those things simply aren't being done (by French authorities)," he said.
The development comes despite Sussex Police saying they are working with authorities across Europe to find Mr Forrest and 15-year-old Megan.
There have been no reported sightings of Megan or her teacher since the pair crossed into France, and they could be anywhere in Europe, police have said.
Detectives searching for them have stressed their primary concern was to bring the teenager back unharmed.
Sussex Police Chief Inspector Jason Tingley, said: "Although they entered France, it is possible that they are elsewhere now. Therefore our objectives are to identify where they are and for them to contact us, so we can bring Megan home safely".
The news comes as 30-year-old Mr Forrest's father also called for the pair to get in touch and return home.
Speaking from his home in Kent, Jim Forrest told reporters his son was "a gentle and caring" man who was extremely vulnerable.
"I am worried about Jeremy. I am not worried about Megan. I can tell you my son is one of the most gentle, caring people you will ever meet. I worry for him more than Megan in case he flips."
Megan's "bucket list" of 50 life ambitions has been discovered online. The final item on her wish list - to "fall in love" - had been crossed out.
Conflicting reports have suggested police may have been aware of the pair's relationship for some time and that their mobile phones were seized before they fled.
However, it now seems just one phone was taken for examination but it is not clear whose it was.
Police reportedly told the Daily Mirror: "The first time police were aware of any concerns about Megan and Mr Forrest was last week and we have been liaising with the school since then.
"We do know that she has spoken about perhaps going somewhere."
Former students at Bishop Bell Church of England School told Sky News that Megan should return home.
"I just think that she should come home. I know it could be scary because what's going to happen to Mr Forrest but I can tell by the news that her family is really worried about her," said former pupil Shanice Dolan.
Another former pupil, Will Jacobs, described Mr Forrest as "really nice", adding that students at the school were "shocked" by what had occurred.
There have been claims that Megan and the married maths teacher had been close for up to seven months.
They were allegedly seen holding hands by pupils during a flight from Los Angeles after a school trip in February and one of Megan's friends said another classmate had raised the issue with school staff.
The school's headteacher, Terry Boatwright, said the school had been investigating the issue before the pair left the country.
"The school, in conjunction with the local authority, Megan's parents and the police, had been investigating those concerns when this happened," he said.
But Megan's mother Danielle Wilson, 37, said she knew nothing of the alleged affair until her daughter ran off with Mr Forrest.
Photos have been released by police of Megan and Forrest on a ferry at 9.30pm last Thursday which show them walking hand-in-hand.
Police believe Megan left the UK willingly and urged her and Mr Forrest to contact them.
Chief Inspector Tingley appealed for any members of the public who see the couple or Mr Forrest's black Ford Fiesta, registration GJ08 RJO, to get in touch.
Psychologist Dr Linda Papadopulous told Sky News that once the pair elected to run away, their relationship and commitment to each other was likely to grow.
"Once they've decided to take that plunge, it's them against the world. As a consequence, that depth of relationship and inter-dependence, is going to get stronger."
:: Anyone with information is asked to call Sussex Police on +44 1273 475 432 or text +44 7786 208 090.