"Ant & Dec's DNA Journey" will hit screens in the autumn.
The 43-year-old TV presenter's new 90-minute show - which will see them tracing their family history in a bid to learn more about their heritage - was shot in 2017 but was later halted after Ant was arrested for drink-driving.
ITV boss Kevin Lygo said: "We had to stop filming as they hadn't quite finished it, but I've seen the first part and it's absolutely brilliant.
"They've got a bit of filming to do to finish it and it should go out late in the autumn - it will be a big thing.
"We test their DNA and they go back and find relatives they didn't know about. The DNA profiling is so accurate and detailed."
Ant, 43, took time off from work commitments following a drink-driving conviction in March last year and a stint in rehab.
The TV presenter returned to work in January 2019 alongside his regular co-host Dec to front the "Britain's Got Talent" auditions.
However, ITV bosses confirmed last year there will be no episodes of "Ant and Dec's Saturday Night Takeaway" in 2019 as the star's break from TV meant there was no time for the duo to prepare for the show, which would have aired in spring.
And Kevin has now said the show will be replaced by extra episodes of "Britain's Got Talent" and Dermot O'Leary's "Small Fortune" rather than one programme.
He is quoted by the Daily Mirror newspaper as saying: "We've mixed and matched - it would be such a curse on some poor sod if they had to be "Oh, I'm the new "Takeaway"."
Ant - whose marriage with make-up artist Lisa Armstrong ended in 2018 - previously revealed he was secretly drinking in order to cope with the "stresses and strains" of his life.
He confessed: "Life hit me hard. I was going through a lot of personal stuff that was very publicised.
"The problem is you take something or you drink to escape from an underlying unhappiness."