Tweet-happy swimmer Michael Phelps Saturday expressed surprise he was unaffected by China\'s ban on Twitter -- and said many Chinese fans were breaching the country\'s Internet controls to read his posts. Phelps said he had expected not to be able to use Twitter, which is banned in China along with Facebook after authorities blamed the sites for stirring ethnic unrest in 2009. But he said he had been able to access the service since arriving in Shanghai this week for the world championships, and had also set up a Chinese \"weibo\", or microblog, on a local equivalent. \"I just turned my phone on and it worked so I just started tweeting,\" he said. \"But I just opened up a weibo account recently and I\'m on there too and everything from my Twitter is going right there so you guys can follow that way as well.\" He added: \"It is actually funny when I do randomly get a couple of tweets (from Chinese fans) that say we\'re doing like a sneaky thing just to be able to read your Twitter.\" Phelps joined other athletes who had set up Chinese accounts, including diving star Tom Daley and fellow Briton Jack Laugher. The 26-year-old Phelps said he had taken some persuading before he finally succumbed and signed up to Twitter but was now a committed fan. \"There were a lot of people that were trying to get me on Twitter for a long time. I kept saying \'no, no, I\'m not doing it\' but I eventually gave in this past December and it\'s been fun and we\'ve finally got my mum on it too.\"