The game attracted only 16,000 fans and cost the Auckland region $1.8 million, just a month after John Key was first elected Prime Minister. During the visit, Beckham spent 45 minutes with Key's son Max.
But a source close to Beckham claimed he barely remembers meeting Key.
"David isn't sure he spent much time with him at all," the source said. "He remembers the previous leader Helen Clark a lot better."
A spokesman for Galaxy said the club had never heard of Key and their star player was too busy preparing for a weekend match to get involved.
The PM's remarks have generated worldwide headlines. Britain's best-selling tabloid The Sun led with the story.
Key yesterday tried to distance himself from his remarks as he attended a fundraising event at a Devonport bowling club in Auckland.
"I have nothing to say," he shrugged. "It was a personal comment and I am not going to engage in talking about something that someone thought they heard me say."
Brian Lloyd, bat survey officer for Forest and Bird, said Key's remarks were "an insult to bats and to Beckham".
"Bats are pretty intelligent. Their droppings are rich in nitrogen and produce their own ecosystem. And they are anything but thick."
Max Cryer, author of popular Kiwi linguistic books, said he thought the PM had got his words mixed up and a more common expression was "boring as batshit".
"He may have meant to reference pig shit, which is a far more widely used term," Cryer said.
"He perhaps should check what he is saying before getting it wrong and accusing other people of being thick.
"David Beckham has made hundreds of millions of dollars from his off-field business activities and you would think John Key would be aware of that."
