Even by Jarryd Hayne's walking-headline standards, a storyline involving the NRL star, a school presentation and pornography would have been considered completely unimaginable.

Until Monday at least.

Hayne was left embarrassed after the homepage of an adults-only website appeared on a big screen in front of 200-plus students while the Titans fullback was presenting an online safety talk at a Gold Coast high school.

Hayne tried not to laugh as the images, including lewd acts and a topless woman, remained on-screen for a number of seconds before the former NFL player held his phone aloft to protest his innocence.

Students burst into laughter before a female teacher did her best to calm them down.

"It was (awkward)," Hayne admitted.

"I shut my phone straight away so that way I was logged off."

Hayne and his phone were part of a demonstration at Robina State High School, highlighting the dangers of joining open WiFi networks when the mishap occurred.

The porn website appeared over the top of Hayne's active browsing, featuring mainly sports images, as it was being captured on a laptop.

Norton Security's Nick Savvides, who was presenting the talk, said afterwards the images had come from another device that had entered the network.

Mr Savvides said the offending device was a Samsung, while Hayne was using an iPhone.

"It's unfortunate and all I can say (is) it definitely was not Jarryd's device," he said.

Norton is investigating how the incident occurred.

The original demonstration was set up to show how "middle men" could seize data and view any ongoing activity on phones while connected to public networks without the user's knowledge.

"Connecting to open networks, people can see what you're doing and in this case, inject unwanted materials," Mr Savvides said.

School principal Julie Warwick later confirmed the device did not belong to anyone in the room.

"I am disappointed that students were exposed to the images," she said in a statement.

"The school will be offering support to any students who need it.

"I have been assured by the external provider that they will reflect upon this to ensure this does not happen at any future school presentations."

It's not believed Hayne is to give further talks at other schools.

The demonstration has been shown before without Hayne and Mr Savvides said such an issue had not arisen before.

He could not confirm how many people could have had access to join the network, however it was possible its range could have extended well outside the school.