Watch: Victoria Beckham reveals alleged affair was 'most unhappy I have ever been
In the four-part series, titled Beckham, the Spice Girl-turned-designer addressed the speculation that David allegedly had an affair while he was playing for Real Madrid in 2003, according to The Sun.
The couple, who married in 1999 and share four children together, have always denied claims of an affair.
In extracts of the documentary shared with The Sun, Victoria spoke about how the allegations impacted their relationship, saying: “It was the hardest period because it felt like the world was against us.
“Here’s the thing — we were against each other if I’m being completely honest.
“You know, up until Madrid sometimes it felt like us against everybody else but we were together, we were connected, we had each other.
“But when we were in Spain, it didn’t really feel like we had each other either.
“And that’s sad. I can’t even begin to tell you how hard it was and how it affected me. It was a nightmare.
“It was an absolute circus — and everyone loves it when the circus comes to town right? Unless you’re in it.”
When the singer was asked if she “resented” her husband, she replied: “If I’m being totally honest, yes I did. It was the most unhappy I have ever been in my entire life.”
The woman former England captain David was accused of having an affair with is not named during the documentary, which is launching on Wednesday, according to the newspaper.
In the documentary, David also addresses how the speculation affected them individually and in their marriage.
He said: “There was some horrible stories which were difficult to deal with.
“It was the first time that me and Victoria had been put under that kind of pressure in our marriage.”
The couple were joined by their children at the premiere of the documentary in central London on Tuesday evening.
Victoria, who dressed in a crisp white suit, and David, who donned a dark suit and tie, posed for pictures alongside their children Brooklyn, Romeo, Cruz and Harper as well as Romeo’s girlfriend Mia Regan and Brooklyn’s wife Nicola Peltz.