The country needs fewer, better paid police officers to fight crime effectively, the Institute for Security Studies (ISS) said on Tuesday.

Swelling police numbers over the past few years was not necessarily having the desired impact, ISS crime and justice programme head Gareth Newham told Parliament's portfolio committee on police.

"We are not of the view that the reduction of police numbers over the next few years is a bad thing because you really do want to have fewer, better paid, more professional police officers than much larger numbers of people you can't control."

Newham was briefing MPs on the South African Police Service annual report.

He said the massive hiring approach in SAPS since 2002 was as a result of communities wanting to see more visible policing.

"There's a lot of political pressure to do this [hiring] and that's not unusual in countries experiencing high crime rates."

Newham said there were various problems that stemmed from creating so many new posts.

"You [are] recruiting around 19 000 people a year and it means the ability to vet those people, to select the right ones, weakens...."

He said the increase in the number of shift commanders did not lead to better management.

"The less of that command control you have, the less professional ethos, and it's easier for people to get corrupt and do things for their own gains."

This created perceptions that police were generally corrupt and officers could not be trusted, Newham said.

"For every one police officer that is corrupt it creates a bad impression among 100 civilians."

He said studies were needed into why, despite bad pay and working conditions, some officers remained true to the profession.

"I'm more amazed at how many police officers are not corrupt given the conditions they work under and how easy it is to be corrupt, but they're not."

Newham said stamping out corruption had to start at the top and the SAPS needed a no-nonsense approach when it came to holding their most senior officials accountable.

"When police look up and they're looking for guidance and they see people misleading commissions of inquiry or whatever, and no action is taken against them... that sends out a very strong message that it's not about how professional you are, it's about who you know and how connected you are...."

This led to a police culture where people protected each other, refused to take action against their corrupt colleagues, and bent the rules.

Newham said in the end it was about telling police they were doing a crucial job, paying them well, and reminding them that they were professionals.