A European arrest warrant has been issued for Jeremy Forrest, the 30-year-old maths teacher who fled Britain with 15-year-old Megan Stammers.
Further details of the warrant are set to be released during a news conference later today.
The couple may now be in Spain, with the Serious Organised Crime Agency (SOCA) contacting counterparts in Madrid for help, The Telegraph reports.
Missing: Megan Stammers blows a kiss to the camera
France has open borders with Spain, as well as Germany, Italy, Belgium and Switzerland.
The last confirmed sighting of Stammers and Forrest - who taught maths at Bishop Bell C of E School in Eastbourne, East Sussex - was from CCTV cameras on board a Dover-to-Calais ferry at 9.30pm last Thursday.
The release of two images of the pair, arm in arm and holding hands, was intended to trigger a response from the public about their whereabouts.
But there have been no further sightings, police have said.
Jeremy Forrest, performing under the name "Jeremy Ayre"
At the news conference, Chief Inspector Jason Tingley will also speak about the inquiry into the missing pair and "clarify the status" of the European inquiry.
It comes amid confusion over how intensely the search is being carried out on the Continent, with reports claiming that French police are not actively looking and have not carried out standard credit card or mobile phone checks.
CCTV images from the Dover-to-Calais ferry revealed the pair holding hands
BBC News reported that Interpol was unable to confirm that it is working on the case.
Neither Megan nor Forrest has a profile on the crime agency's website under its "yellow notices" section which "help locate missing persons, often minors, or to help identify persons who are unable to identify themselves".
Nor is Forrest listed under the website's "red notices" - profiles used "to seek the location and arrest of wanted persons with a view to extradition or similar lawful action".