A class 12 student from a western Sydney private school is being investigated after he was allegedly caught live-streaming an exam on Facebook from inside the examination hall.

The student who allegedly filmed the Information Processes and Technology (IPT) exam was contacted more than a week after the alleged incident by the New South Wales Education Standards Authority (Nesa), which conducts the HSC exams.

Nesa has now given him and his school a chance to make a statement, the Brisbane Times news website reported.

"Nesa has received information that a student witnessed a live stream of you during the 2017 HSC Information Processes and Technology exam," an email, which was sent by a senior project officer in Nesa's student support services branch, read.

"We are currently investigating the matter and would like to offer you the opportunity to make a statement in regards to this matter.

"Should you wish to make a statement, please complete the attached form and email it back to me as soon as possible.

"Should you choose to not make a statement, the matter will proceed without it."

A teacher is also said to have tweeted to Nesa on the day of the exam saying "hey #NESA - FYI there's a student live-streaming their IPT exam right now on Facebook".

The video has now been deleted from Facebook.

The principal of the institution the student belonged to said in a statement said that the school was contacted about the incident on Friday by Nesa.

"[The] school is very disappointed [about] the possibility that one of our students might have been involved in this incident," the principal was quoted as saying by the Brisbane Times.

According to Nesa rules and procedures, using any electronic device during the exams can result in the student getting zero marks or losing their HSC. Mobile phones, smart watches and tablets are some of the items banned from exam rooms.

These exams are supervised by staff employed and trained by Nesa. Around 7,500 supervisors are working this year across NSW.

The IPT exam was held on 24 October and about 2,748 students had enrolled for this course.

According to Nesa, last year's exams also saw students taking photos or videos of the exam papers and posting them on social media. Around 14 serious issues related to the usage of electronic devices during an exam took place last year.