A new integrity unit being set up by the Hong Kong police will carry out financial checks on officers and may ask them to submit to voluntary drug tests, the force’s deputy chief has told the South China Morning Post.

The stepped-up supervision comes after nearly 20 officers were arrested over the course of a few weeks for a variety of offences, including possession of drugs that may have been stolen from a crime scene.

While warning that officers who broke the law would be held accountable, Deputy Commissioner Oscar Kwok Yam-shu defended the reputation of the 31,000-strong force, saying its character was better than that of police in major overseas cities, such as New York or Chicago.

Kwok also accused the media of singling out the force after a few senior officers were accused of violating building or land rules, saying it was an attempt to undermine the organisation’s reputation. The Land Department found irregularities at properties tied to assistant police commissioner Rupert Dover and his family, as well as one where Chief Superintendent David Jordan lived.

“But I would say this is a futile effort. I’m not trying to downplay the transgression,” Kwok said. “We routinely train and advise our officers to behave up to the highest possible standard, precisely because of this, in public and private life.

“Let the chips fall where they may. Everyone will have to account for his own behaviour and bear the consequences. Police officers are the same.”

The integrity of the force came under the spotlight when 18 officers were arrested within three weeks from April, prompting the police chief to set up the new supervisory unit.

Headed by an assistant commissioner, it will investigate disciplinary offences and identify potential loopholes that officers might be tempted to exploit.

The unit was in the process of selecting 15 members, who would then be vetted. Apart from acting on complaints or intelligence, the team will select specific units within the force and audit their operation, administration and the integrity of its members.

Officers’ financial situation will be checked and they may be invited to submit to voluntary drug tests.

“The intervention measures are to plug loopholes for people who have ill intentions, to create an atmosphere that if you are up to no good, you stand a very high chance of being discovered,” Kwok said.

“If someone is financially in a bad state, of course he will be at risk of succumbing to temptations. So we need to know for certain special posts … It will be prudent to know whether anyone we posted in these places is under financial strain. Drug tests are another one we are considering.”

Two of the 18 officers were arrested for possession of HK$12 million (US$1.55 million) of crystal meth that police sources believed was taken from the scene of a recent record seizure. Police chief Chris Ping-keung Tang earlier said he was “outraged” by the officers’ alleged illegal acts.

Across all of last year, 24 officers were arrested, but Kwok said the situation was not so severe when looking at the number across a decade. What was more important, he said, was transparent management and that police openly published figures on the number of officers arrested and routinely monitored the matter.

Citing research, Kwok said the number of arrests per 1,000 officers in Chicago was 6.22 over a six-year span and 5.44 in New York, whereas in Hong Kong, the number stood at 1.26.

Earlier this month, the force’s watchdog released a long-awaited report on the anti-government protests, concluding there was no systemic problem in policing. The use of force was only in response to the violence of protesters, it found.

The Independent Police Complaints Council (IPCC) made 52 recommendations, including a review of operational command structure, clear guidelines on the use of weapons and a task force to advise on the frequent use of tear gas.

But a five-member panel of international experts advising the IPCC on its investigation resigned last year over concerns about its limited powers.

When asked whether the report amounted to justice for the police force, Kwok said the document provided justice to Hong Kong people as it was the first authoritative and scientific attempt to lay out facts.

“Our actions will speak for ourselves. I think history will judge us fairly in the long run,” he said.

The Security Bureau will lead a meeting with police on Thursday to set priorities in following up the recommendations.

Chief Executive Carrie Lam Cheng Yuet-ngor has said enhancing the police’s capability in monitoring social media was another top task. Kwok agreed there was not enough legislation on the matter, adding that more technology and new rules were needed as it was difficult to enforce laws against online criminal behaviour. Rules should “dictate” the behaviour of app developers and website hosts as they were the gatekeepers, he said.

One member of the panel, Clifford Stott, who is director of the Keele Policing Academic Collaboration at Keele University in Britain, has announced he will compile a separate report on the unrest.

Stott criticised the police for using disproportionate force at “practically every” anti-government protest and making poor decisions in dealing with them.

While respecting Stott’s right to freedom of speech, Kwok questioned his motive as the academic had only been in Hong Kong a few days and did not have access to materials given by police.

The professor attended briefings, a lecture on crowd psychology and discussions with the IPCC team during his stay in Hong Kong, according to Kwok. But the deputy chief said hewould still read Stott’s report out of public interest.

“It only concerns me now because he is obviously one of those people whose objective is to undermine the ability of the police force to do its job. If he’s so getting in the way of us protecting our citizens, that for me is a big deal.”