Vets tranquilised the lions so they could be assessed by police forensic teams, with the park's anti-poaching unit scouring the area for clues.
It is believed the men entered the reserve in the early hours on Monday to poach rhino.
He added that it's unknown how many poachers there were, as "there's not much left of them", according to BBC.
Unfortunately for the would-be poachers, "the lions are our watchers and guardians, and they picked the wrong pride and became a meal", according to Fox. Several lions in the vicinity were tranquilised in order for authorities to investigate the scene further.
"Clearly, the poachers had walked into a pride of six lions and some, if not all had been killed", according to a Facebook post by Fox.
PRESS RELEASELions Kill Suspected Poachers on Sibuya Game ReserveSometime during the night of Sunday 1st and early... "They use the rifle to shoot the animal and the axe to remove the horn".
Sadly, rhino horn is apparently under increasing demand in Asia for its supposed qualities as an aphrodisiac.
More than 7,000 rhinos are known to have been poached in the past decade.
The reserve is one of the most popular game serves in the Eastern Cape and is home to Africa's big five - elephants, buffalos and leopards as well as rhinos and lions.
Together with neighbouring reserves, owner Nick Fox has formed the Association of Eastern Cape Reserves (Indalo) - which just a month ago was given protected status as part of South Africa's overall conversation efforts.