The New South Wales Education Standards Authority is investigating after some HSC students received access to their results early by mistake.

Preliminary results, which were were due to be released on Thursday morning, could be accessed by some students on Saturday morning.

A NESA spokesperson confirmed to 9News a preliminary set of HSC results were available for students to view "for a short period".

READ MORE: Teen dies after stabbing at social occasion on NSW South Coast

"NESA is investigating the cause of the issue and sincerely apologises for any inconvenience caused," the spokesperson said.

"Final HSC results will be released this Thursday."

Students discussed the leak in HSC discussion groups on social media and shared the link which allowed them to see their marks.