Al Fahim sent the club a resignation letter earlier on Monday.
In the letter, he wrote that he had not been made aware of the club’s financial situation despite repeated requests.
The letter from Al Fahim states that he was "ignored” by board members as he tried to ascertain the true state of the club's finances. "Discussions between board members were taking place on a daily basis and I was not being invited to participate," he says in the letter.
Portsmouth will return to the High Court to defend a winding up order from the Inland Revenue on March 1. It faces debts of over $50m.
Al Fahim took control of the club in July last year but 42 days later sold 90 percent of the shares to Saudi businessman Ali Al Faraj. He stayed on as chairman with a 10 percent stake.
Earlier this month, Hong Kong businessman Balram Chainrai became the club’s fifth owner in eight months.