Ant McPartlin and Declan Donnelly have celebrated the return of Saturday Night Takeaway by pranking Simon Cowell for a second time – more than 20 years after their first.

The music mogul was the Geordie duo’s first prank victim in 2003 when they pretended to be a funny audition on US singing competition American Idol, where Cowell was a judge.

To mark the start of the show’s 20th series, the pair returned to the States to prank Cowell on his bicycle ride and during filming for America’s Got Talent (AGT).

McPartlin and Donnelly will take a break from the show at the conclusion of the series as they feel it is the “perfect time to pause for a little while and catch our breath”.

As they opened the show, Donnelly said: “I actually can’t believe the first episode of Saturday Night Live was almost 22 years ago” before they showed a photo of the pair from June 8 2002 – their first show.

They then turned the tables on their audience, showing pictures from years ago of people sitting in the studio and at home watching the live show.

The duo also revealed they handpicked every member of the 411-person audience, which was filled with foster parents and fundraisers.

As a thank you to the live audience, who they said had collectively raised £40 million for charity, they gifted them all a getaway prize.

Later in the show, they brought out Cowell who admitted he never thought the pair, who he works with on Britain’s Got Talent, would try to prank him again.

“We’re friends! I never in my wildest dreams thought a) you would do it or b) that you would actually make me not work it out – I fell for it,” he said.

The first prank saw Cowell interrupted on his morning cycle by a fake police officer, whom McPartlin and Donnelly fed instructions to through an earpiece while they sat in a van nearby.

The officer accused him of breaking a series of made-up misdemeanours including that his bicycle did not comply with Malibu colour regulations – which they claimed were seafoam blue, seafoam green or seafoam white – and that he needed to carry his bicycle licence with him.

The second stage saw the music producer pranked on AGT in front of a live audience when a fake magician act got him to get into a metal box which they locked with chains.

The fake masked performer then pretended to swallow the keys and told Cowell that they had got stuck in his throat, which left the judge unimpressed.

The AGT stage crew members then pretended to attempt to cut him free with a chainsaw, frustrating him further by asking if he consented every time they went to take his safety glasses on or off throughout the process.

Just before they were going to try using explosives, McPartlin and Donnelly took to the stage in disguise as the masked performers.

They said: “This illusion did not go to plan for this TV show but it did go to plan for our TV show in the UK” before revealing they were behind the prank, causing Cowell to say: “I am going to kill you.”

McPartlin told him: “This is payback for 20 years of keep us waiting Simon Cowell.”

Afterwards in the live studio, Cowell said: “I swear on my life, this is how stupid I am, I had no idea what was going on. That whole day was just a total nightmare.”

As he left, he told the duo: “I hate you, I love you.”

The show also teased that to mark the 20th series, the segment I’m A Celebrity Get Out Of Me Ear will see stars including Cowell, Amanda Holden, Holly Willoughby and Rylan Clark get their own back on McPartlin and Donnelly.

Elsewhere in the show, McPartlin and Donnelly went head to head in a challenge which saw them climb up a scaffolding structure which was suspended in the air.

McPartlin was the first to reach the top and press the buzzer, putting him in the lead at the start of the series.

Comedian and actor Stephen Merchant joined the show as the guest announcer for the week while presenter Stephen Mulhern made a dramatic return to the programme dressed as the character Dr Evil from the Austin Powers film series.

Becky Hill closed out the show by singing a medley of her hit songs including Disconnect and Remember while dance collective Urban Theory performed around her.

McPartlin, Donnelly and Mulhern also got involved by performing the hand choreography alongside the group.

Ant & Dec’s Saturday Night Takeaway continues on ITV.