KANSAS CITY, MO - OCTOBER 07: Patrick Mahomes #15 of the Kansas City Chiefs reacts after carrying the ball into the endzone for a touchdown during the game against the Jacksonville Jaguars at Arrowhead Stadium on October 7, 2018 in Kansas City, Missouri. (Photo by Jamie Squire/Getty Images)

The Kansas City Chief have given Super Bowl-wining quarterback Patrick Mahomes a 10-year contract extension reportedly worth between $US477 million and $US503 million.

It is the richest sports contract in the world.

Mahomes has two season left on his current contract; with the 2020 season worth $2.8 million, which is slated to start in September, and the 2021 season worth $24.8 million. He signed the contract while he was a rookie.

According to ESPN, the new contract is worth at least $US450 million; but the remaining value on his current contract and the bonuses linked to the new contract means the dollar figure could end up over US500 million ($AU716 million).

This led to Mahomes’s agency, Steinerg Sports, to call its client the “first half billion dollar player in sport history” on Twitter.

The contract extension begins in 2022 when the NRL cap is project to be $227.5 million, however, the figure could be lower due to the coronavirus pandemic impact on revenue and whether games this season will have fans.

Selected with the 10th pick in the 2017 NRL draft, Mahomes has since won the league’s Most Valuable Player Award in his second season, led the Chief’s to their first Super Bowl win in 50 years and was named the MVP of this year’s title game.

“Since he joined the Chiefs just a few years ago, Patrick has developed into one of the most prolific athletes in all sports,” Chiefs chairman and chief executive Clark Hunt said.

“With his dynamic play and infectious personality, he is one of the most recognised and beloved figures to put on the Chiefs uniform.

He’s an extraordinary leader and a credit to the Kansas City community, and I’m delighted that he will be a member of the Chief’s for many years to come.”

The contract extension will take up a large chunk of the Chiefs salary cap, seen as around 20 per cent, making the possibility of signing other big stars difficult. According to general manager Brett Veach, the big figure won’t make the Chiefs a one-man team.

“We’re going to continue to do everything we can to surround him with talent, and this deal provides us more flexibility to do that,” Veach said.

“He’s obviously an integral part to our success and we’re thrilled he’s going to be the quarterback of Kansas City Chiefs for a long time.”

The big figure doesn’t take into account Mahomes’s endorsements, which include lucrative deals with Adidas and Oakley.