US regulator the Federal Communications Commission (FCC) is launching an investigation into "pay for play" practices in the music industry.
Britney Spears' parent company Sony BMG was fined by the FCC
It follows an inquiry into improper practices by Sony BMG, which saw the record company agree to pay a settlement of $10m (£5.7m) last month.
FCC chairman Kevin Martin said he was "very concerned" about the activities.
"If the bureau determines violations of the payola rules have occurred, the commission will take swift action."
The FCC investigation was prompted by New York Attorney General Eliot Spitzer, who led the probe into Sony BMG and other music groups.
Mr Spitzer urged the FCC to take action over improper payments in the music industry, and has even suggested violators should be stripped of their broadcasting licences.
Under a 1960 law, record companies in the US cannot offer undisclosed financial incentives in return for playing songs.
"These rules serve the important purpose of ensuring that the listening public knows when someone is seeking to influence them," said Mr Martin on Monday.
Kevin Martin was named FCC chairman earlier this year
"Broadcasters must comply with these rules."
"The airwaves belong to the public, not the highest bidder," said FCC Commissioner Jonathan Adelstein.
"The vitality of radio is sapped when music is selected based on bribes rather than merit."
A Sony BMG spokesman was not available for comment.