Janet Jackson's breast flash made indecency a hot issue in the US

The move comes after widespread outrage following Janet Jackson's infamous breast-baring incident.

A new law had already proposed to raise fines from $27,500 (�15,000) to $275,000 - but a Congress committee has now voted 49-1 to change that to $500,000.

Full Congress and Senate must approve the law before it comes into force.

The vote to increase the proposed fines was taken by the Congress' House Energy and Commerce Committee on Wednesday.

Radio DJ Howard Stern was accused of being "insulting"

Committee chairman Representative Joe Barton said: "Personal responsibility is as important a freedom as free speech.

"America's responsible parents seek to raise their children with a strong sense of responsibility for their actions - why should performers be excluded from this expectation?"

If the bill becomes law, TV and radio broadcasters could be fined $500,000 each time they air indecent material.

There has been a strong reaction in the US after several recent broadcasts - such as Janet Jackson's "Nipplegate" - caused offence.

Radio "shock jock" Howard Stern has been dropped from six radio stations owned by Clear Channel after the company said he conducted an "insulting" interview.

Zero tolerance

The company also fired Florida DJ Bubba the Love Sponge after a sexually explicit conversation between spoof cartoon characters on his show.

Clear Channel, the largest US radio station operator with more than 1,200 outlets, recently adopted a "zero tolerance" policy.

At Wednesday's Congress hearing, Representative Albert Wynn, a Maryland Democrat, said the fines "would provide further incentives to licensees to better address these issues".

And Representative Fred Upton, a Michigan Republican, said they would "deter companies from pushing the envelope of appropriate broadcasting".