Charges of crimen injuria against National Police Commissioner Jackie Selebi would be probed by the Independent Complaints Directorate, Selebi's office said on Tuesday.
Spokeswoman Director Sally de Beer said the ICD was perfectly placed to handle the investigation as it was independent from the SA Police Service.
"This will help ensure a credible and objective finding," she said in Pretoria.
The Democratic Party earlier called on Selebi to go on leave pending the outcome of the probe into charges that he swore at a Pretoria policewoman on New Year's eve.
"It is too much to expect that the inquiry can be concluded impartially with the new commissioner on duty," the party's safety and security spokesman Graham McIntosh said in a statement.
He questioned Selebi's motives for declining to elaborate on the incident by "hiding behind" the sub judice rule.
"If he really called the policewoman a 'f... gorilla' he should be man enough to admit it and apologise," McIntosh said.
"Instead he is subjecting himself and the SAPS to a long process which is not in the interest of South Africa."
Selebi allegedly swore at a female sergeant on duty at Pretoria's Brooklyn police station after he demanded a driver but was not recognised.
The woman, identified as Sergeant Jeanette Mothiba, has laid a charge of crimen injuria against her new boss.
On Sunday Selebi said the charge resulted from "an unfortunate incident of mistaken identity". He said it would be improper for him to elaborate as the case was sub judice.
The DP's Gauteng branch said in a separate statement it was understandable that Selebi was not as "recognisable" as he would have liked.
"I have sympathy with the sergeant who apparently failed to snap to attention upon his entrance. I for one would not know the face of Mr Selebi, who has now been in office for a mere four days," according to public safety spokeswoman Shelley Loe.
"If Mr Selebi felt that it was so important to be instantly recognised by police throughout the country, I suggest that he issue a clear head and shoulder photograph of himself to be displayed in all police stations." - Sapa