New York Police Commissioner Ray Kelly says there were never any problems with delayed security payments when he was police chief, calling into question Rudy Giuliani's explanation regarding some suspect billing practices.

Critics allege that Giuliani would submit police security expenses to obscure city agencies, rather than to the NYPD, while he was mayor of New York City to help hide his affair with his then-mistress, Judith Nathan. Nathan also was given use of a police driver and city car.

Giuliani says he adopted the practice only to speed payment of American Express credit card bills, because the NYPD was late in processing payments for Giuliani's security detail.

But Kelly says that's news to him.

"I don't recall anybody, any statements about delay," Kelly told reporters, stating that it never as an issue when he was police chief under Giuliani's predecessor, David Dinkins.