Pirates announced the signing of Obiozor in June on a three-year contract.
However, according to sources close to the matter Obiozor was offered to Bucs as a free agent when he had an existing deal with Enyimba.
"Obiozor is back in Nigeria. He is issued with a contract with Enyimba," says a source.
New Buccaneers coach Milutin Sredojevic confirmed Obiozor is no longer training with the team but could not provide a reason for his departure.
Sredojevic's men will start their 2017/18 Premiership campaign against Chippa United at Orlando Stadium on Saturday (18h00).