Chainrai became the fourth person to control the club this season on Thursday after becoming frustrated at not receiving payments on a 17 million pound loan he made to his predecessor Ali al-Faraj via the Portpin company.
"I have zero interest in buying Portsmouth and it's completely untrue that I am the new owner of the club," he told Friday's South China Morning Post.
"As far as I am concerned, I have just confiscated the shares of the previous owners.
"It's nothing to do with controlling the club. I don't know anything about running a football club. I just love the game and that's why I've taken this action. We have exercised our right to take control of the shares, and to remove the previous owners."
Portsmouth are banned from buying players because of money owed to other clubs while the players and staff have regularly had their salary payments delayed this season.
Five points adrift at the foot of the Premier League, they are also fighting a winding-up order from the British Government's Revenue and Customs department.
Chainrai said he had seized al-Faraj's 90 percent interest to protect Portsmouth and his priority was to find a new investor with "the club's best interests at heart."
"Believe me, someone will come in and buy this club. This is Premier League football we are talking about," he told the paper.
"We are eagerly looking for an investor to come in and take over. I don't have a time frame to find a prospective buyer. I would like to have one here today if I could, but we'll just have to wait."
Chanrai was the second Hong Kong businessman to take a controlling interest in a Premier League club after Carson Yeung's Grandtop International Holdings Ltd bought Birmingham City last year.
