Controversial Durban private security company Reaction Unit SA's (RUSA) suspension has been lifted, but only after it was slapped with a R20m fine for improper conduct.

Following a "spate of litigations" and two High Court judgments, the Private Security Industry Regulatory Authority (PSiRA) have got RUSA to concede to charges related to improper conduct.

"We did not anticipate a protracted process in this case, but we are satisfied that our own regulations were put to a test through the courts and were found to be rock solid," PSIRA CEO Manabela Chauke said on Friday.

Some of the charges relate to cases of alleged assault, TimesLive reported.

PSiRA slapped the security company, which operates mainly on the coastline, with a R20m fine, R17m of which has been suspended on condition that RUSA is not found guilty of similar contraventions in the next year.

One of the conditions to lift RUSA's suspension is that an amount of R500 000 be paid on or by Friday, with the remaining R2.4m payable within 24 months.

As part of its punishment, RUSA also issued a public apology.

"[The apology is to] all its victims and the nation for the atrocities it has caused and, moreover, for violating the industry's code of conduct," said Chauke.

He said the case should send a strong message that the regulator would invoke its mandate.

"[We will] exercise effective control over the practice of the occupation of [the] security service provider in the public and national interest and the interest of the private security industry itself.

"The regulator will keep a strong eye on the company and ensure that it complies from now onwards."

In its apology, RUSA said it intended to strictly follow the industry code of conduct going forward.

"We regret any violations of this code of conduct in the past and will strive to adhere strictly to [it]. We further wish to make public that every member of RUSA that violates the COC will be subject to strict disciplinary measures, including being suspended where necessary.

"It is our intention to be the best we can be and conform to the regulatory authorities' expectations of us without weakening our resolve to fight crime and honour our mandate to the public.

"We also want to place on record our apologies to any member of the community whose rights have been violated on any occasion in our zeal to fight crime. This is regretted."

The company had its licence suspended in early September.