Hayman was the second former senior Met police officer to be questioned at the Leveson Inquiry today over drinking champagne with a News of the World reporter.
Earlier this afternoon former assistant commissioner John Yates spoke of drinking champagne with the former crime editor Lucy Panton who was arrested by officers investigation illegal payments to police.
Hayman, who was in charge of Operation Caryatid, the Met's 2006 phone-hacking investigation, was asked about a meeting, thought to be with Panton or the female journalist covering for her while she was on maternity leave.
"I can't remember the event", Hayman said, not able to say which News of the World reporter he met during the 2007 dinner at Oriel restaurant.
Counsel for the inquiry Robert Jay asked Hayman if putting £47 on his Amex to pay for champagne was not "going too far in entertaining a member of the press".
Hayman spoke of the need for a relationship between the media and the Met.
The Leveson Inquiry into press standards, which is currently focussing on the relationship between the press and police, heard of a number of other dinners.
Hayman had dinner with Panton in November 2005 to discuss an article about the threat of terrorism.
In March 2007 he had lunch with Panton and Neil Wallis, former deputy editor of the News of the World, who was arrested in July. After leaving the News of the World and before his arrest Wallis was given a job as a PR officer at the Met.
In August Hayman was criticised by IPCC chair Deborah Glass for his "social contacts with News International and subsequent employment by the Times".
Hayman was also asked by the inquiry about how regular his contact was with his deputy Peter Clarke, the head of the anti-terrorism unit during the 2006 Operation Caryatid investigation into hacking.
Hayman said he could count "on one hand" the contact he had with Clarke.