Various sources are reporting that Fat Joe started his four month prison sentence Monday.

The rapper was ordered to serve time in jail for tax evasion and Joe, whose real name is Joseph Cartagena, is currently in federal police custody at a Miami detention center.

Fat Joe plead guilty in June to failure  to pay income taxes on more than $1 million for the years of 2007 and 2008.

In addition to serving time, Joe also was ordered to pay a $15,000 fine.