Jessica Biel wore a "real" Justin Timberlake outfit for Halloween.

Jessica Biel and Justin Timberlake

Jessica Biel and Justin Timberlake

The 'Sinner' actress dressed as her husband with her pals as his *NSYNC bandmates for the spooky holiday last week and she added authenticity to her transformation by digging out the jumpsuit he wore to the 1999 American Music Awards as her costume.

Speaking on 'The Late Late Show with James Corden', she said: "I surprised Justin because I remembered that we have that exact jumpsuit that he wore in storage.

"So we pulled it out and it was the real one. It's for real. It's the real jumpsuit...

"I was working in New York so I literally was flying back on Halloween night. I had missed my flight. The whole crew of all our friends being the band members were waiting on me to get there and I was late.

"So my friends threw my outfit in the car. I went from the airport. I changed in the car."

Despite Justin's surprise at his wife's outfit, the 37-year-old star revealed her costume theme was actually the 'SexyBack' hitmaker's idea.

Asked how he reacted, she said: "This was his idea. It was all his idea."

James didn't think such a suggestion would have gone down so well with his own wife, Julia.

He laughed: "I can't imagine my wife's face if I went, 'You know what you should dress as? Me.'

"She would divorce me so fast. She'd divorce me in a heartbeat."

While Jessica dressed up as Justin, her spouse - with whom she has son Silas, four - went as a mic and the actress admitted it caused him a lot of problems throughout the evening.

She said: "He wore the hugest costume, it was so funny, he could barely move.