After a three-year crusade to clean up its notoriously corrupt police department, the Hong Kong government has stepped back to avoid a head-on confrontation with the only large armed force holding together this volatile urban mix of East and West. The brief crisis of protest rallies, hallway scuffles, reported police slowdowns and alternately soft and hard responses from the British governor, Sir Murray MacLehose, seemed to dissipate early this week almost as quickly as it had materialized.

Over a tense weekend, however, it served to remind Hong Kong's 4.4 million residents, almost all of them Chinese, of their uneasiness about the 20,000-member police force.

In a city full of racial and political tensions where mere rumors of instability can threaten a bustling economy, there are only about 3,000 resident British troops to call on when the police fail, and most of those are Nepali-speaking Gurkhas handicapped in dealing with a Chinese-speaking population.

The police protest also reflected the vigor, unheard of in most other large cities of the world of the anti-corruption effort here. Since 1974, when the government created the Independent Commission against Corruption, investigators have received more than 10,000 corruption complaints, about 8,500 of them dealing with police. Through last week the commission had made 334 arrests including 260 police officers and 230 civilians charged with bribing public officials. According to the commission, which has an annual budget of $11 million, 129 police officials have been convicted, 79 acquitted and at least 52 others still await trial.

Untold hundreds of other policemen remain under investigation, despite Sir Murray's crisis-defusing decision Saturday to grant amnesty, with some exceptions, to anyone guilty of corruption prior to this year who had not yet been called in by the corruption commission.

Policemen have complained of broken homes and suicides resulting from worries over the investigations. They say the public has shown no appreciation for past exploits like the crucial police action against Communist inspired rioters in 1967 or sympathy for young officers forced by corrupt superiors to take payoffs or lose their jobs.

"We have been let down," said one senior officer. "We have been abused, insulted an d scorned for years."

Last year the police began to gather some sympathy from the business community as the commission began to move against sales kickbacks, often traditional in Chinese commerce but made illegal by one section of Hong Kong's Prevention of Bribery ordinance.

On Oct. 25, when 34 policemen including three British superintendents were arrested to climax a sweep of three alleged major corruption syndicates, disgrunted officers - including many charged with corruption - began to organize mass rallies. Oct. 27, 5,000 officers met and voted to march on police headquarters and press demands for a voluntary legal defense fund and an end to what they considered strongarm tactics by commission investigators.

Police commissioner Brian Slevin received a march delegation the next day and agreed to some demands, but shortly after about 100 policemen in civilian clothes stormed the corruption commission's headquarters and assaulted some investigators, injuring five.

The attack was denounced by businessmen, the press and the government and the police department launched an investigation. Nevertheless, resentment against the commission among officers still simmered. Reports began to circulate Saturday that police had disappeared from the streets in some parts of the city and had received instructions in other places not to act on minor offenses.

Within hours, Sir Murray capitulated. The commission would no longer act on offenses committed before this year, he said, "except in relation to persons who have already been interviewed, persons against whom warrants have been issued, and persons now outside Hong Kong." Several ex-policemen taking refuge in Taiwan reportedly began to make plans to return home at first word of the amnesty, then sobered up when they heard the full text.

When some police leaders suggested further job actions to push for amnesty, the press and business community reacted with outrage. Sir Murray called an emergency session of his Legislative Council which gave the government power to immediately fire any officer disobeying an official order. The policemen's organizations called off further demonstrations, ending the revolt for the time being.

Government sources say that Peking, which has the ultimate say about anything that happens here, made no sign of interest in the dispute. "They'd prefer to have the white imperialist British handle such sticky problems," said one longtime observer.

The British and Westernized Chinese bureaucrats and businessmen who run this city were left to ponder the future of relations between Hong Kong's police and people. "They are the largest organized group, they're heavily armed, and this is the Third World, you know," said one uneasy British resident.

Sir Yuet-keung Kan, the senior representative of the local community on the governor's Executive Council said: "under the influence of a small number of men, the police had brought Hong Kong to the brink of catastrophe. While the force is to be commended for now stepping back, [they remain] under the censure of the entire community."