The married teacher missing with his teenage pupil might not have been identified under a new law that comes into force next week.
Teachers will become the first group of people in British legal history to be given automatic anonymity when they are accused of a criminal offence.
The move could hinder searches like the one for missing teacher Jeremy Forrest, who is thought to be in Europe with his 15-year-old student Megan Stammers, said critics.
The provision, in section 13 of the Education Act 2011, gives anonymity for a teacher when the complaint is made by or on behalf of any pupil at the school at which the individual teaches.
The anonymity remains in place until the individual is charged, but can be lifted if an application is made to a magistrates' court.
Bob Satchwell, executive editor of the Society of Editors, condemned the implementation of the provisions as an attack on freedom of speech.
"It will be a criminal offence for anyone - pupil, parent, police, school, local authority, whistle-blower, media - even to inform parents or the general public that an identified teacher has admitted that the allegation is true and has resigned, has been disciplined, or even cautioned for the offence," he said.
Parents would even be banned from discussing the allegations with their neighbours or other parents with children at the school, Mr Satchwell said. And the accused teacher could be disciplined, sacked and move on but unless they are charged with a criminal offence, no one could name them and even the new school might not be allowed to know there was a problem, he added.
From Monday it will be a criminal offence to publish anything which would identify a teacher who has been accused of assaulting or sexually abusing a child at his or her school if that teacher has not been charged with a criminal offence.
Meanwhile, Mr Forrest's father Jim, of south east London, fought back tears as he begged his son or the teenager to call or email home. He said: "Hi Megan, hi Jeremy, I hope this message reaches you and you are both OK. There are a lot of people back home that are desperate to hear from you. All I am asking is for one of you to make a call, send an email, so we know you are both safe."