Former Cosatu general secretary Zwelinzima Vavi and EFF leader Julius Malema are plotting to overthr.
Yesterday, in response to a barrage of questions from the police portfolio committee, Mkhwanazi said there was no need to provide extra security for the detectives because they had guns to defend themselves.
These are the police probing murder and fraud charges against Mdluli, who was placed back into his position last month after a lengthy suspension - even though a murder inquest against him was still pending.
Mdluli, Lieutenant-Colonel Omhle Mtunzi, Samuel Dlomo and Colonel Nkosana Ximba were last year arrested and charged with murder and defeating the ends of justice.
ACDP leader Kenneth Meshoe said Mdluli's return was likely to have scared witnesses from testifying against him and could also put the lives of detectives who were tasked with investigating the case at risk.
But Mkhwanazi said the police's capacity to protect citizens would be severely hampered if they were expected to provide security to thousands of their detectives.
"If indeed we are going to provide protection to every officer, there will be less police protecting citizens," said Mkhwanazi, adding that the Mdluli detectives were allowed to go home in possession of their service pistols as a security measure.
"There are mechanisms that we do deploy in [certain] instances to try and protect our members. But the protection is limited, it cannot be like [that of] a minister where you have protection 24 hours."
Mkhwanazi also defended the deployment of several members of the now disbanded Durban organised crime unit, which operated from Cato Manor, to the elite crime fighting unit the Hawks.
The MPs blasted the redeployment of the Cato Manor team to the Hawks, saying it could compromise the specialised crime unit.
But Mkhwanazi said they had not been found guilty of wrongdoing by any disciplinary structure of the South African Police Service.
"For now they are still employees of SAPS," he said.