An American woman who established a charity to help vulnerable girls in Liberia has resigned six months after taking a leave of absence in the wake of allegations that a local staffer raped several girls in the charity's care.More Than Me founder and chief executive officer Katie Meyler announced her resignation on Friday in a message on her Facebook page. The organisation confirmed the decision to ProPublica, whose reporting on the rape allegations led Liberian authorities to reopen its investigation and led to Meyler's leave of absence.In her resignation message, Meyler rejected claims she failed to protect students, but said she recognised her public role as CEO "has become a distraction from the critical mission and incredible and proven work of our team"Meyler, 37, started her leave of absence in October after ProPublica reported that former staffer Macintosh Johnson had sexually assaulted students at a More Than Me branch in the Liberian capital of Monrovia. She was to remain on leave until the completion of an independent audit conducted on the charity's behalf.Meyler said on Facebook that she learned about the alleged rapes in June 2014 and "immediately ensured the perpetrator was reported to the Liberian authorities".Johnson "was in jail four days after I learned of his abuse," Meyler wrote. "I cooperated fully with the police investigation and did everything I could to protect our students."Johnson had AIDS and died in jail in 2016 while awaiting trial. ProPublica reported that Meyler and Johnson were once in a romantic relationship.Meyler's work had been praised by Oprah Winfrey, Bill Gates and others. In 2014, Time magazine recognised her as one of the Ebola fighters it named as "Person of the Year".Meyler opened the tuition-free, all-girls More Than Me Academy in Liberia in 2013. The charity has said its operations in Liberia will continue. More Than Me operates 19 schools."While my role as CEO has concluded, I urge every More Than Me supporter to redouble their efforts to help these vulnerable girls. They need our support," Meyler said in her resignation message.Directing part of the message to the girls she founded More Than Me to help, Meyler wrote: "I started this organisation because of my deep and profound belief in you. Please know, nothing can or ever will change that. No one can stop you. You make darkness shutter. Rise, powerful, courageous girls, rise! The world is waiting for you!"