Malaysian Anti-Corruption Commission (MACC) Chief Commissioner Tan Sri Abu Kassim Mohamed has been confirmed to be suffering from back problems and is undergoing surgery today.

The matter was confirmed by a source close to Abu Kassim.

Few blogsites had previously reported that he was on a sick leave and scheduled to undergo surgery.

The media on Wednesday had also reported that Abu Kassim had to go on a sick leave until next week.

Abu Kassim's role will be assumed by MACC deputy chief commissioner (prevention) Datuk Mustafar Ali, until Abu Kassim's return.

The Star had erlier reported that deputy Commissioner (Operation) Datuk Seri Mohd Shukri Abdul had denied that Abu Kassim was ordered to go on leave and said he is overseas on work matters.

MACC is one of the four bodies investigating the alleged transfer of funds into the personal accounts of Prime Minister Datuk Seri Najib Razak and the SRC International, a former subsidiary of 1MDB.

Several MACC officers have been detained and their statements recorded over the purported leak of documents in relation to the investigation on the 1MDB scandal.