Speaking in New York, where he is currently filming an adaptation of a Henry James novel, the actor said that he will do "everything in my power" to hold Rupert Murdoch's News Corporation to account for the phone hacking scandal.
In an interview with The Guardian, Coogan said that he decided to take action upon learning that his phone may have been targeted after "seeing Andy Coulson gaining a modicum of respectability standing next to David Cameron".
He added: "Two years ago I rang my publicist and said, 'Look, there's some information that my phone may have been hacked'. I was told, 'That story's gone away, it's not going to come back and Coulson's at the heart of Downing Street now, he's surrounded by a ring of steel'."
However, the actor forged ahead with the legal action and now his fight is playing a pivotal role in uncovering how high knowledge of phone hacking went at the News of the World, which was shut down by News Corp in July amid a flood of shocking allegations.
Coogan has managed to obtain some crucial evidence in his own case, including details of the actions of Glenn Mulcaire, the private investigator employed by the defunct Sunday tabloid.
Mulcaire was forced by the High Court to write to Coogan detailing who at the News of the World asked him to illegally intercept voicemails left for six public figures - Elle Macpherson, publicist Max Clifford, Liberal Democrat MP Simon Hughes, football agent Sky Andrew, PFA chief executive Gordon Taylor, and his colleague Jo Armstrong.
Under the court order Coogan's legal team are unable to make the names public, but the letter is widely expected to debunk previous claims that only one "rogue reporter" was aware of phone hacking at the News of the World.
Coogan wants senior executives at News Corporation, the former owner of the News of the World, to be held account should the scale of phone hacking be revealed.
"The culture of the people on the shopfloor is reflection of management," said the actor. "It always is. So it may be that certain people haven't committed crimes, but there's a cultural culpability."
He added: "We all know it's not one rogue reporter but it's not even an aberration. Hacking into a victim of crime's phone is a sort of poetically elegant manifestation of a modus operandi the tabloids have."
Coogan has previously been targeted by the News of the World and other tabloid papers, which have published stories about his alleged drug use and colourful sex life.
"I got my arse kicked," he said. "Is it part of a sort of personal vendetta? That's certainly what motivated me in the first place, I won't deny that."
The actor believes that Coulson - who was arrested and bailed in July in the police investigation into phone hacking - was personally responsible for an attempt to trick him into admitting that he had slept with a dancer. The move was later foiled after Coogan was tipped off by the News of the World's former showbusiness editor Rav Singh.
"[Coulson] had this dancer in his office once that I'd spent the night in a hotel with… [she was] calling me [from his office] to try and get me to admit to various things," said Coogan.
"This is not illegal, but it shows you the character of the man. The point is that this is the kind of thing he does. That's not to say he knew about hacking. We don't know this yet. We'll learn about all the details of that in the inquiry."
Coogan said that News Group Newspapers, the News Corp subsidiary which owned the News of the World until it closed in July, had offered to settle his case.
"It wouldn't have covered the costs but it would have taken the sting out of what I'd spent," he said. It is understood that Coogan has so far spent more than £100,000 on his legal case.
Coogan refused to be drawn on Coulson's future or whether James Murdoch, the chairman of News Corporation Europe, should stand down. But he did say that he will use his public profile to ensure News Corp is not able to bury the phone hacking scandal.
"[They are hoping] there will be some big disaster or something that'll knock it off the front pages and hopefully no-one will care anymore. And I will do everything in my power [to prevent that]," he said.
"Because I'm a more populist person and I reach a more generalised audience that goes beyond broadsheets, [so] I can help keep it in the popular imagination and I will do everything in my power to keep it in the popular imagination."