The sex abuse investigation focused on a famous Manchester music school widened today.
Ten people, most of whom taught at Chetham's School of Music or the city's Royal Northern College of Music, are under investigation.
At least 30 alleged victims have now reported historic sexual abuse.
The women came forward following the sex abuse trial of Chetham's former music director Michael Brewer.
Brewer was jailed for six years in March after he was found guilty of indecently assaulting ex-pupil Frances Andrade, 48, more than 30 years ago when she was 14 and 15.
Mrs Andrade killed herself at her home in Guildford, Surrey, a week after giving evidence against him.
The trial heard allegations that sexual activity between teachers and pupils at Chetham's was not uncommon.
– Detective Chief Inspector Jamie Daniels, from GMP's Protective Services Division
This is a significant inquiry in terms of potential number of offenders and number of victims.
We are supporting each and every person who has come forward and made a complaint to us as best we can and I must credit them all for having the courage to face demons that have been haunting them for many, many years.