Farm murders have decreased in the last four years, national police commissioner Riah Phiyega said in Johannesburg on Monday.

"When we refer to data there is a progressive decline in the number of farm killings," she said at the South African Human Rights Commission's (SAHRC's) hearings on safety and security in farming communities.

According to the police's presentation at the hearing, farm murders decreased between 2010 and 2013.

Seventy-one farm murders were recorded during the 2010/11 period in 665 incidents. This fell to 56 murders in 514 incidents in 2011/12.

The number increased to 60 murders in 556 attacks in 2012/13. In the 2013/14 period there were 58 murders in 402 incidents.

Phiyega said government had invested much in the police.

According to the police's presentation at the hearing, all reported cases of violence on farms and smallholdings were captured on a database and analysed for sharing with the rural safety priority committee.

She denied that farm murders were not included in the annual crime statistics.

She said the police followed an inclusive and integrated approach and could not single out farm murders from other crimes.

The Institute for Security Studies said farm attacks were not racially motivated.

"People went to farms to steal, motivated by greed," researcher Johan Burger told reporters in Johannesburg.

He said racial insults were sometimes used during such crimes, but this did not mean race or politics were the motives of such attacks.

He said the phasing out of the commando system had created a vacuum which the current national rural plan was not addressing adequately.

The commandos were South African National Defence Force reservists assigned to ensure rural safety, disbanded by then-president Thabo Mbeki in 2003.

"The problem with the national rural strategy is that it is too broad and under-resourced," he said.

He said no official reason was given for phasing out the commandos, but it was alleged they were aligned to right-wing groups.

"That is incorrect because black people were part of the commandos, although the management was mostly whites."

AfriForum said Phiyega was not in touch with the realities playing out on South African farms.

"Gen Phiyega said farm murders are now fewer than before, and as a result implied that the farm murder situation is not as bad as people think," Ernst Roets, deputy CEO of AfriForum, said in a statement.

"The fact that crime has declined from a high extreme to a somewhat lower extreme does not mean that it's solved. It is our experience at AfriForum that the brutality of farm murders is worsening, but Gen Phiyega didn't make mention of the brutality."

The Food and Allied Workers Union said there was widespread violence on farms and that the living conditions of farm workers were inhuman.

"Farmworkers cannot access social services. They do not have access to safe water and electricity and other services," said Howard Mbana, the union organiser.

He said farmers threatened workers with eviction when faced with laws and policy aimed at improving the lives of farmworkers.

He said it was difficult to attribute farm murders to racism.

"It is not easy to tell whether the incident is racially motivated. In most cases the motive is crime," he said.

The SAHRC convened the hearing because of the evidence seen in the current crime statistics, complaints lodged with the SAHRC regarding violence in farming communities, media reports and other anecdotal accounts, which all pointed to the fact that safety and security, and human rights protections in farming communities still remained a significant challenge.

The hearing also aimed to assess the progress made by both public and private actors on the implementation of the SAHRC's 2003 and 2008 recommendations.