Wishing her best to the outgoing Malaysian Anti-Corruption Commission (MACC) top guns, Bersih chief Maria Chin Abdullah expressed shock that certain quarters are against their efforts.

"What we have are dedicated MACC officers who are committed to fighting against corruption. It is very shocking that their efforts are treated with disdain," Bersih chief Maria Chin Abdullah said in a statement.

Yesterday, MACC’s three top officers - chief commissioner Abu Kassim Mohamed, deputy commissioner (operations) Mohd Shukri Abdull and deputy commissioner (prevention) Mustafar Ali - bid farewell to the agency.

Maria related how a number of MACC officers were detained by police in 2015 in the midst of their investigation into the 1MDB scandal.

They were an ex-MACC adviser, a seconded Attorney-General's Chambers officer, and deputy public prosecutor Ahmad Sazilee Abdul Khairi.

She recalled that the Special Branch even raided Ahmad Sazilee's office and seized several documents related to the 1MDB probe as well as a laptop.

"The climate of fear had certainly stifled good honest civil servants from carrying out their honest duties," said Maria.

She congratulated the outgoing MACC top guns for their perseverance in upholding justice, transparency and accountability.

"This is so well expressed by outgoing MACC deputy chief Mohd Shukri Abdull in his farewell speech," said Maria.

She expressed her sympathy for Abu Kassim, the now former MACC chief, saying he had carried out his duty diligently and truthfully, only to be the victim of slander.

Maria was referring to a police report lodged on Tuesday, claiming the former graft-buster head was part of a plot to topple Prime Minister Najib Abdul Razak and his government.

"The police report made by Umno Youth is totally uncalled for and sheer wanton behaviour.  Those who made the police report have lost all sense of rationality for what is the truth and justice," said Maria.

Abu Kassim will continue to serve as an anti-corruption service officer until his mandatory retirement in 2020.

It is understood that Shukri has retired from public service.

Meanwhile, Mustafar has been appointed as the new Immigration Department director-general effective Aug 1, replacing Sakib Kusmi who has been transferred to the Public Service Department.

Dzulkifli Ahmad, a senior officer with the Attorney-General's Chambers, will be the new MACC chief commissioner.