A discovery made on the next episode of The Curse of Oak Island could be the biggest ever find in the history of the legendary treasure hunt, it has been revealed.

According to History, the potentially game-changing discovery is made by Rick Lagina and metal-detecting expert Gary Drayton and is thought to be an item in the shape of a cross which the pair were shown finding among rocks on the shore of Oak Island at the end of the latest episode.

When it was handed to Rick by Gary, he said: “I’ve seen that shape before — in the Templar prison in France.” A close-up was then shown of one of the engravings made by imprisoned Templar knights at the guardhouse in Domme, France — which was visited by Rick last episode. It featured a figure in the shape of a cross.

Get our The Curse of Oak Island newsletter!

The scene where the item is found also features in a new sneak peek for next week’s episode, which is titled The Signs of a Cross, where Gary hands Rick the object saying: “What the heck is this? Holy shmoly alright.”

The pair are then seen high-fiving by the water’s edge, before Gary tells Rick: “We might have just made history.” In a separate scene, Marty Lagina is seen saying: “This is incredible.” He adds: “It fits in every aspect.”

It’s thought the item is the same “mysterious medieval cross” referenced in the description for the episode that airs in two weeks’ time, titled Moving Targets.

Here are the descriptions for the next two episodes from History:

The Signs of a Cross — air date January 16, 2018

The team unearths a ship’s log detailing the burial of treasure on an island eerily similar to Oak Island, and Rick and Gary make what may prove to be the biggest find on Oak Island, ever.

Moving Targets — air date January 23, 2018

Further investigation suggests a link between the mysterious medieval cross and the Knights Templar.

The sneak peek at the end of the latest episode showed local area historian Doug Crowell talking about the “ship’s log” mentioned above, which read: “It has been agreed that a deep pit be dug and treasures securely buried, the pit to have a secret entrance by tunnel from the shore.”

We also saw footage of a conversation which revealed that the huge 50in caisson the team are drilling down into what they believe is the original Money Pit hits something at 170ft underground.

That is just below the level of where they believe the so-called Chappell Vault — a supposed vault uncovered by previous treasure hunters William Chappell and Frederick Blair in 1897 — could lie.

The new trailer for the next episode also includes footage of the same scene, where the caisson is said to be sitting on a “flat, hard surface”. Marty Lagina is heard saying: “This could be the vault?”

At the site, Marty Lagina is also seen asking brother Rick: “How are you feeling?” Rick says: “Nervous.” He adds in an interview with producers: “After all of the work that we’ve done, this is the culmination.”

Watch the trailer for the next episode of The Curse of Oak Island below!

Tuesday at 9/8c They may have just made history. Posted by The Curse of Oak Island on Thursday, January 11, 2018

The Curse of Oak Island airs Tuesdays at 9/8c on History.