Instagram photo suggests Max Key might have proposed

This Instagram image of Max Key and his girlfriend Amelia Finlayson have sparked engagement rumours. Photo / Instagram

Rumours are rife on Instagram that Max Key has proposed to his girlfriend - but he's been known to prank followers before.

An Instagram image shows the Prime Minister's son with his girlfriend Amelia Finlayson on the summit of the Haleakala volcano on the Hawaiian island of Maui.

It shows the pair holding hands, with Max Key - who turned 20 in May - looking downwards at his girlfriend's hands.

He's hinted more images of their holiday venture will soon be made public.

"Amelia and I have been putting together a video from some of our adventures which will be dropping next week. Stay tuned for more."

Followers speculated he had proposed.

One person wrote: "Proposing to your girl in the middle of a lava flow".

Another said: "Looks like a proposal hehe".

And a third asked: "care to share?"

In January Mr Key, an aspiring DJ, used his Instagram account to prank followers.

He posted what appeared to be a photo of himself out for a round of golf with someone who looked like Dan Bilzerian, an American trust fund beneficiary, poker player and part-time actor who is facing criminal charges in the US.

But it turned out to be one of Mr Key's friends who resembled Bilzerian.

Media outlets had reported it as being him.

Mr Key and his girlfriend have been holidaying on Maui, where the Key family has a holiday home, this week.

Miss Finlayson has also shared some snaps on Instagram of their holiday getaway.

She's depicted snuggling with her boyfriend on a spot overlooking a beach.

"What a lucky girl I am...@maxkey_has taken me to paradise."

Press secretary says the Prime Minister is on holiday and she won't be speculating on what's been found on Instagram.