Controversial yes, fraud I don't think so. His methodology and demeanor were non conventional at the least, and those he authorized abused his trust and did things their own way, whatever way to get promoted and follow the hawa' and nafs, even from his children, family members, and close ones. As for kufriya statements as a sufi a lot are apparently wrong, unless you do taweel, and its not even a ridiculous amount needed. Personally, I have been old elite scholars and sufiyya abstain from any verdicts but do acknowledge his methodologies should not be mimicked rather critiqued, ghumrah or deviant, but he is not a kafir. As for the "mureedeen," unless they are tullab ul ilm, there opinions and actions just highlight their jahalat. Alhamdulillah unlike his father, Shaykh Mehmet is more staunch and has different methodology. Unfortunately, the jahil mureeds from their fathers time are still around and have ruined the chance for "tariqah" recovery. No matter how much he tries, the mureeds are not really going to change as they are in their own fantasy idea of tasawwuf which fancies their nafs. This is the state of 98% of the tariqah as a whole. Unless you are really advanced in knowledge and are high up their in psychological literacy, stay far away from this tariqah. And stick to a path that will actually help in destroying the nafs and not empowering it.