South African Test cricketer Zubayr Hamza has tested positive for a prohibited substance under the International Cricket Council (ICC) anti-doping code after a Test conducted in January, Cricket South Africa said on Wednesday.

Last week Hamza, 26, was left out of the South Africa Test squad announced for a two-Test series against Bangladesh starting starts next week, with "personal reasons" cited as the reason.

"Zubayr is not disputing the positive test, is co-operating fully with the ICC, and has agreed to a voluntary suspension commencing immediately whilst written submissions are presented to the ICC," Cricket South Africa said in a statement.

"The positive test relates to the substance Furosemide, which is not a performance enhancing substance, and Zubayr has been able to identify how the substance entered his system.

"The process to follow will entail presenting evidence that there was no fault or negligence, or no significant fault or negligence on the part of Zubayr," it added.

Hamza has played six Tests and a single One Day International for South Africa.