A friend of missing 15-year-old Megan Stammers allegedly warned school staff about her relationship with her married maths teacher, seven months before the two ran away to France, after they were seen holding hands on a school trip.
Megan was apparently spied hand-in-hand with Jeremy Forrest, 30, on the plane home from a five-day-visit to Los Angeles with the school.
Megan's parents have always denied they had been told anything about the pair's relationship.
A spokesman from East Sussex County Council admitted that the school had been aware of concerns about the teacher's relationship with Megan, but would not confirm for how long.
A text message was sent to a friend of Megan saying she had arrived in France after she is believed to have eloped with her maths teacher, it was disclosed.
Megan Stammers' parents were visibly upset as they appealed for their daughter to return
The message was sent to one of her good friends saying she was in France but did not come from her own phone, a senior police officer revealed on Monday.
Chief Inspector Jason Tingley of Sussex Police said: "I can't give a specific time or date but we know there was a message passed to one of her good friends to say she had arrived safely in France.
"I can't say that message was from her but we believe it was. That gives us some comfort that she has arrived safely and she is in France. That's our last contact."
The Daily Mail reported that Forrest had been "under investigation for several months and was expected to be suspended last Friday, the day after the pair vanished."
Jeremy Forrest, performing under the name "Jeremy Ayre"
It also reported that wannabe musician Forrest had written a song, Better Company, referring to the hand-holding incident.
In it, he sings: "Sitting on the plane, we were miles away from the things you hate, but girl I'd do it all again, I'd hold your hand, put up with the friend, don't think that I won't."
A friend of Megan's at the Bishop Bell C of E School in Eastbourne, East Sussex, told the Daily Mail: "They would always text each other. He would send her messages saying things like "I miss you" and "I can't wait to hug you".
"We are really angry the school did not do enough to protect Megan. And now no one knows where she is or if she's coming back.
"I don't know how it all started with Mr Forrest but to begin with she was really excited about it.
"She would tweet about being in love and show us his texts. But after it was reported she stopped and then deleted her Twitter account. She never spoke about it after that and she didn't tell any of us that she was leaving. She probably knew we would stop her."
Child protection expert Mike Hames said reality would have hit Megan by now and hopefully she would see through the media that the whole country is worried about her.
"If you just treat it as going on holiday with somebody then after a few days reality starts to come back," Mr Hames told ITV Daybreak.
"Maybe she's starting to think 'What am I doing?'
"She would already be missing her parents.
"She obviously loves her mum so hopefully this separation that she's undergone in the last few days will actually wake her up to the fact that she wants to go home again."
Help with the search via the Twitter hashtag #findmeganstammers. Police have asked the pair, or anyone else with information, to call them on +44 1273 475 432 or text +44 7786 208 090.