A remorseful Blaskowski, who ran 100 metres in 9.89 this summer, apologises in an Instagram post where he writes that he is ashamed.
"There are no excuses and I take full responsibility for it," the 23-year-old writes about the racist jokes he shared on social media around seven years ago and which have now resurfaced.
Blaskowski is one of the most promising sprinters in the United States and is now forced to leave his training group in Florida.
"Star Athletics has no tolerance for racial discrimination or bullying and takes this seriously. We have actively analysed the situation internally and determined that the only right thing is for Sam Blaskowski to leave Star Athletics," the team writes in a comment.
