A trio of stars from series past of I'm A Celebrity... Get Me Out Of Here! have reportedly been drafted in for mystery roles in the upcoming new series.

Joey Essex - fourth-place finisher in 2013 - and former winners Charlie Brooks and Vicky Pattison are said to have been isolating in Wales ahead of the show starting this weekend.

According to The Sun, the three celebs have not been told their exact role on the show yet but ideas under consideration include having them stay as guests for a night or getting them to host a bushtucker trial.

"ITV producers love having a trick or two up their sleeve," a source told the newspaper. "What better way to celebrate 20 series of the show than getting some of the stars of yesteryear to take part in some way?

"As always with the jungle, they're keeping their cards close to their chest and have yet to decide exactly what they will do with Charlie, Vicky and Joey, but it could be any number of things.

"They told them they had to spend some time isolating, just like this year's contestants have done, ahead of being taken up to Wales.

"There's even a chance they'll isolate, travel to Wales, and not even get used. But it's three great options for producers to have in the locker."

The new series starts this Sunday at 9pm on ITV.