A school girl at the centre of a sex scandal at a Gauteng school might have left the institution several years ago‚ police said on Tuesday.

An image showing the schoolgirl kissing the former principal of Reiger Park NR 2 High School has been widely distributed on social media.

Lieutenant-Colonel Heila Niemand said investigators had reason to believe the picture was taken around three years ago when the girl was a Grade 12 pupil at the school.

Niemand said police were still working on verifying whether she was below the age of 18 when the incident happened. If so‚ the principal‚ who left his job two weeks ago‚ would be charged with numerous counts‚ including manufacturing child pornography.

The principal submitted his resignation in October and left on January 15‚ allegedly after videos and pictures of himself with a learner‚ teachers and other school employees in compromising positions were leaked on social media.

"No criminal charges have been formulated as yet. We are still trying to identify the victims... Investigations are still at an early stage‚" Niemand said.

Psychologists from Child Line and the Teddy Bear clinic have been at the Boksburg school since Monday‚ trying to identify whether there were any other students who allegedly fell prey to the principal who had been at the school for 15 years.

By Tuesday‚ none had come forward. But at least three other teachers have been implicated in the sex scandal.

"All the implicated teachers have been removed from the school and all the officials depicted in the videos have been withdrawn and will report to the district‚" said Gauteng Education MEC Panyaza Lesufi.

His spokesman Steve Mabona said that the teachers had admitted that they consented to performing sexual acts with the principal on school premises.

However‚ Lesufi highlighted that the food handlers who were also implicated "were among the victims".

Meanwhile‚ the department of education was still liaising with its lawyers to change the principal's resignation to a dismissal.