[3] The ICAC has played a crucial role in maintaining Hong Kong's reputation as one of the least corrupt places globally and fostering a culture of integrity within the city.

It investigates complaints of corruption-related offenses, conducts operations to uncover corrupt practices, and has the authority to arrest, search, and seize property.

[6][3] In addition, the ICAC works on preventing corruption by reviewing and improving systems and procedures in government departments, public bodies, and private organizations, while also offering advice and assistance in implementing effective anti-corruption measures.

[3] As Hong Kong recovered after World War II, the population began to swell and manufacturing industries grew.

In response, Godber immediately arranged for his wife to leave the colony, then used his police airport pass to bypass Immigration and Passport checks and walked onto a plane for London.

Godber's escape led to a large public outcry over the integrity and quality of the police's self-investigation and called for reforms in the government's anti-corruption efforts.

[8] The newly formed Independent Commission Against Corruption would be answerable to only the Governor of Hong Kong, unlike the old police Anti-Corruption Branch.

[9] The move received a mixed response from the public whilst being broadly supported by legislative councillors as being in the best interests of Hong Kong not to let the affair fester and further demoralise the police Force.

[10] Urban Council member Elsie Elliot criticised the government for being lenient to senior corrupt officials, punishing only "small flies."

In the late 1980s, the Acting Crown Prosecutor, Charles Warwick Reid, was arrested for taking bribes to throw trials.

He, his wife and his solicitor became the defendants in a landmark Privy Council case[11] on tracing bribe money in 1993, when the Attorney-General of Hong Kong sought to obtain unpaid fines of $12,000,000 by claims on land Reid bought in the New Zealand seaside town of Tauranga.

The investigative, preventive, and educational activities of the ICAC no doubt also had some impact but were not solely or even largely responsible for reducing police corruption.

[12] After the big purges of the 1970s, many thought that the ICAC would take a reduced role in society, but despite the fact that their main job was done their influence remained pervasive.

Short of voluminous numbers of dramatic cases many ICAC officers left Hong Kong, others remained to enjoy a less taxing life.

However, in 1993 their deputy director of Operations Alex Tsui Ka-kit was suddenly sacked by Governor Chris Patten, who stated that he had "lost confidence" in Tsui—a euphemism that strong evidence of corruption or significant wrongdoing existed.

Indeed, he made counter-allegations of misconduct within the ICAC, one of which was that Director of Operations Jim Buckle had "squashed" an investigation into allegations of sexual harassment by an officer called Michael Croft (who was later transferred and forced out of the service).

The LegCo committee expressed its concern as to "whether Mr Tong had thoroughly considered that unduly close contacts between him and mainland officials in Hong Kong during his tenure might have shaken public confidence in the impartiality of the ICAC.

[16] Chief Secretary Carrie Lam admitted that the controversy surrounding the over-expenditures "inevitably undermined the ICAC's image and Hong Kong's reputation as a corruption-free society.

More importantly, in 2014, Maria Tam, former colonial loyalist who rapidly switched allegiance to Beijing after 1997, was named head of the Operations Review Committee – a key board that has power to question any decision of the ICAC and to drop any case.

All covert surveillance operations of the ICAC are now carried out strictly in accordance with the ICSO, which applies to all law enforcement agencies in Hong Kong.

[17] Currently headed by Ricky Yau Shu-chun, this department considers itself all powerful, and has apparently resisted all attempts to interfere with its investigations.

[citation needed] The investigation into circulation fraud by Sally Aw at The Standard has been cited as an example of the embarrassment caused by such non-co-operation with the government hierarchy.

To be the member of R4, investigators have to undergo a battery of physical, written, and psychometric tests, and receive a three-phase training if they are selected, which involves multiple tactics in witness protection, firearms and more.

ICAC commissioner Dr Timothy Tong Hin-ming mentioned in a report tabled in the Legislative Council the strategic importance of information technology (IT) in operations as corruption cases have become increasingly complex.

In 2008, the commission organised a series of seminars to enhance the investigators' knowledge on the global and local financial system and its regulatory mechanism.

Prevention wise the ICAC offers advice and practical help to enable companies and organisations to introduce systems and procedures that are resistant to corruption.