NSW Treasurer Michael Costa is suing morning radio hosts Merrick and Rosso's station, Nova, over claims aired on their breakfast show that he had seen a prostitute, the Supreme Court has confirmed.



The duo's real names are Merrick Watts and Tim Ross.

Last month an anonymous caller, who said she was a prostitute, alleged on their show that she had "seen" Mr Costa.

She was responding to a question by Watts, who had asked why prostitutes did not reveal the names of their high-profile clients.