Federal investigation is ordered into Janet Jackson's boob at Super Bowl

America was in a tizzy last night over the exposure given to Janet Jackson, one of the performers in the half-time show at Sunday night's Super Bowl.

With a little help from Justin Timberlake, with whom she was singing a duet, she let slip a little too much flesh - her right breast, adorned with a metal "solar medallion".

It was clearly too much for the arbiters of decency on prime-time television. By last night the incident was the subject of a federal investigation. Michael Powell, the chairman of the Federal Communications Commission, called the brief display "a classless, crass and deplorable stunt". CBS, the network that screened the game was moved to issue an apology. Leslie Anne Wade, a spokeswoman, said: "CBS deeply regrets the incident."

Timberlake, who was in the midst of a flirty duet with Jackson when he reached over and ripped open her costume to reveal her breast, blamed a "wardrobe malfunction".

Never mind that as he made the move, he was singing: "Better have you naked by the end of this song", a line from his hit single "Rock Your Body".

The show, which is watched by millions of Americans every year, was produced by MTV. The National Football League said it was unaware that such a display was planned and suggested that MTV would never be invited to produce a half-time Super Bowl show again.

Mr Powell said: "I am outraged at what I saw during the half-time show of the Super Bowl. Like millions of Americans, my family and I gathered around the television for a celebration. Instead, that celebration was tainted ... Our nation's children, parents and citizens deserve better."

There was no comment from Jackson. Which left Timberlake to explain. "I am sorry that anyone was offended by the wardrobe malfunction during the half-time performance," he said. "It was not intentional and is regrettable."

On MTV's website before the game, the choreographer of the show promised that Jackson's performance would include "some shocking moments".