Gordon Smart, editor of the Sun's Bizarre showbiz column, has claimed the "nature of celebrity" means that privacy is often outweighed by public interest.
He told the Leveson inquiry into press ethics that showbiz reporters were always "walking the line" between public interest and a celebrity's right to privacy and revealed that "trivial" stories might not be fact-checked.
He also said that the paper had a duty to uncover hypocrisy when it came to the behaviour of celebrities, who are often viewed as role models.
"We write a lot of trivial stories, so there's a grey area there [regarding privacy] . If it's not particularly damaging, I would see it as fair game to report it. It might not be in the public interest," he said.
Robert Jay, QC, asked Smart if he felt a responsibility to report on a "role model" only if a celebrity were openly outspoken about a cause that they then undermine.
"Is it your position that if the story is trivial, then the celebrity is fair game to report on and regardless of issues of privacy?"
"Yes, I would say it is," Smart responded.
He claimed that the paper had a "duty" to report some stories, such as film star Hugh Grant's visit to a hospital's accident and emergency department.
Jay went on to ask about a pair of spoof stories - one claiming that Girls Aloud singer Sarah Harding had been spotted reading a Stephen Hawking book and another about Guy Ritchie having injured himself in a restaurant while juggling with cutlery - leaked to the Sun and published despite being untrue.
"The interesting thing is that I know both of these people personally," Smart replied.
"With Sarah Harding I was in her house just last week and she actually had quite an impressive library."
He said the inaccuracy of claims of Ritchie juggling cutlery was "trivial" when the story was accurate that he had been drunk in the restaurant.
"You might say that the whole thing is trivial," said Jay.
"I agree that it's trivial and I find it incredible that we are even discussing this," Smart replied.
"We are discussing someone making up a story that they know to be untrue. That is not trivial," Lord Justice Leveson interjected.
Smart continued to claim that the "truth" of the stories was not known, despite them having been fabricated.
"It would be quite remarkable if a story was made up that was known to be untrue and then coincidentally was true," Leveson added.
"It's Bizarre, that's the name of the column," Smart replied.
He stressed that he took privacy and accuracy "extremely seriously", adding that social networking sites highlighted inaccuracies almost immediately, though he admitted that some "trivial" stories would not be checked.
He also said he had no knowledge of any phone hacking taking place at the Sun.