The 50-year-old British actor told the BBC that Paul McMullan took photos of him and boasted that his phone had allegedly been hacked by the tabloid.
'I was revolted and astonished,' said Hugh, who then came up with a cunning plan to meet McMullan in a pub a few months later.
'I pretended to be dropping in for a pint,' he explained, and then got the editor talking about the hacking while he recorded the conversation. He then took his story to the New Statesman.
But McMullen mocked Grant's efforts. 'It was hilarious - how can Hugh Grant coming into your pub with a silly little pen trying to record you be anything other than hilarious?' he said.
'I didn't mind being turned over [but] you can't believe that an actor who's very well-known would lower himself such those tactics,' he joked. 'I was shocked and outraged!'
But the actor told McMullan, 'You didn't care who got hurt so long as you were able to sell your newspaper. You're not journalists, you have no interest in journalism. It's just money, money, money.'
'That's not true at all,' the editor replied. 'Our interest was writing truthful stories.'
'You should try real journalism because you're not an idiot, Paul,' Grant said. 'You could probably do it.'