Liverpool is investigating striker Nathan Eccleston for tweets about the Sept. 11 attacks.
The 20-year-old Eccleston posted the comments on Twitter on Sunday, the 10th anniversary of the attacks in the United States.
''I aint going to say attack don't let the media make u believe that was terrorist that did it,'' Eccleston tweeted.
He also made a reference to O.T.I.S., which can mean Only the Illuminati Succeed. The comments were later removed, but have been widely repeated online.
Liverpool's principal owner is John Henry, whose Fenway Sports Group also owns the Boston Red Sox.
''The club takes this extremely seriously,'' Liverpool said. ''Senior club officials have informed Nathan Eccleston that we are undertaking an investigation into the circumstances surrounding these postings and will decide on an appropriate course of action pending that inquiry.''
Eccleston has yet to play for the first team this season. He made his first-team debut in a League Cup match against Arsenal in October 2009.
