At least 959 teachers and school staff have been accused of having a relationship with a pupil in the past five years.
That's according to figures obtained by Newsbeat after a Freedom of Information request to local authorities in the UK.
In at least 254 cases, there were police charges but it is not clear how many of these led to a prosecution or a conviction.
One charity, The Lucy Faithfull Foundation, said it was not surprised but unions say many claims are false.
Here trainee teachers from the University of Roehampton discuss some of the issues with Newsbeat's Anthony Baxter.
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