South African police are hunting the gunmen who killed one of its top rhino poaching investigators in an ambush.
Lt Col Leroy Brewer's killing was "senseless" and a "huge loss", police chief Gen Khehla Sitole said.
He had "always excelled in cracking complex cases, particularly related to rhino poaching", Gen Sithole added.
South Africa has seen a fall in poaching in recent years after stepping up efforts to protect the animals.
A total of 594 rhinos were killed for their horns in 2019, compared with 769 in 2018 and 1,028 in 2017, official statistics show.
Rhino horns are in huge demand in Asian states such as China and Vietnam, where they are used in traditional medicines.
Most of the poaching takes place in the world-famous Kruger National Park, which borders Mozambique, according to campaign group Save the Rhino.
Who was Col Brewer?
In 2016, he was named the best detective in the Hawks, an elite police unit which investigates organised crime.
Col Brewer investigated poaching syndicates in the Kruger, as well as syndicates involved in ambushing armoured vehicles transporting cash from banks.
He was driving to work when he was shot dead by gunmen with high-calibre weapons on Tuesday. He died on the spot.
Gen Sithole had ordered a "multidisciplinary" team of investigators "not to rest until Col Brewer's killers are brought to book", the police chief's office said in a statement.
His colleagues have described him as a lover of nature, and a highly skilled investigator.
He is said to have fearlessly investigated other policemen suspected of being linked to poaching syndicates.
A local newspaper reports that when he arrested two policemen in 2016, he could not take their fingerprints and charge them because other officers refused to co-operate.
Instead, they locked him and a co-investigator in the same cell as the arrested officers, the report says.
"I banged on the walls for ages until someone came to help us," Col Brewer was quoted as saying in court at the time.
In 2018, he played a key role in the arrest of two suspected rhino poaching kingpins, including a former policeman.
He said in court that he had been assaulted by protesters demanding their release on bail, local media reports say.