"We suspect two were killed, possibly three", Sibuya owner Nick Fox said on Thursday.
A hunting rifle with a silencer attached and a long axe and wire cutters were recovered at the scene by police. "At the same time, the handler heard a loud commotion coming from the lions, so he suspected that this was what had alerted her and was not concerned", Fox said.
"We thought they must have been rhino poachers but the axe confirmed it", Mr Fox said.
"In a Facebook post, Fox said the poachers entered the reserve either late Sunday night or early Monday morning, noting that they had what he called "... all the hallmarks of a gang intent on killing rhino and removing their horns".
The poachers were apparently on foot when they encountered the lions, which is very unsafe.
The poaching problem has gotten so bad that some conservationists have begun flying black rhino - the most endangered type of South African rhino - through the air, upside down, by helicopter to safer turf.
Then, on Tuesday afternoon, one of the field guides found what appeared to be human remains near the lions' range.
The game reserve is one of the most popular in the Eastern Cape, and it is visited by many British tourists. The firearms have been taken by the police for examination, to find out if they have been used in poaching before.
He added that it's unknown how many poachers there were, as "there's not much left of them", according to BBC.
In 2016, the reserve lost three rhinos when poachers got into the park and shot them dead and cut off their ivory horns.
In 2017, poachers killed 1,028 rhinos in South Africa, compared with 13 in 2007.
Rhinos are targeted to feed booming demand for rhino horn in China, Vietnam and other Asian countries, where it is believed to have medicinal qualities.