Raleigh Radio: Paris Rants About Bob Dumas

Paris Hilton went ballistic after a WDCG- 105.1 FM radio interview Thursday morning ... launching into an expletive-filled rant against the DJ who had just interviewed her ... calling him a "f**king a**hole" ... without realizing she was still live on-air.

Paris was on the phone with a Bob Dumas and the morning Showgram in Raleigh-Durham and midway through the interview, Dumas asked: do you wish you had never made that sex tape?

Paris was annoyed ... but kept her cool ... blaming it on her XXX co-star Rick Salomon ... and calling him "a very sick man."

But, according to TMZ,  Paris couldn't get off the phone fast enough ... and when she mistakenly thinks she's hung up and is off the air ... she goes off on Dumas ... who's listening to the whole tirade.