Jessica Biel was horrified when she found herself "sandwiched" between two "husky" naked men in a Swiss spa.

The actress married her long-term beau Justin Timberlake in Italy in October. Before the week-long festivities began, Jessica decided to take a friend to the Swiss Alps so they could relax and ensure they looked their best for the big day.

They went to a retreat, where they indulged themselves by taking to a sauna. The 30-year-old was a little perturbed when two men walked in and things soon took a turn for the worse.

"We're in the spa, in the sauna and in walked two husky Austrian men...OK, I thought this is a little unusual but we're in Europe...I didn't really know what the protocol was. They drop their towels - they are butt naked," the star recalled to talk show host David Letterman, adding she was clad in a bikini.

"Older, husky men - they were naked and I'm in the middle of them! I was so stunned... I just laid there sandwiched in between these [guys]. We found out later this is very normal."

Biel and Timberlake splashed out a rumoured $6.5 million on their nuptials, which were celebrated over a week in the Borgo Egnazia resort in Puglia, Italy.

They flew their guests to the country and managed to keep the details of the wedding secret until after it had happened.

The pair even refused to talk about their wedding date, with Jessica admitting she was amazed they pulled the whole thing off.

"[We] wanted to keep it as much of a secret as we could...so I kinda got really obsessed with this CIA operative kind of scheme," she laughed.

Biel wore a custom-made, pink Giambattista Valli Haute Couture wedding gown, with Justin dressed in a Tom Ford tuxedo. He also penned a special song for his new bride, which he sang on their special day.

- Cover Media