The Democratic Alliance wants Police Minister Fikile Mbalula to make the shortlist of candidates for a new permanent Hawks head public, so as to avoid any "surprise announcements".
The position was left vacant after Major-General Berning Ntlemeza was forced out in April following a ruling by the North Gauteng High Court in Pretoria that his appointment was irregular and unlawful.
President Jacob Zuma's "surprise appointment" of Lieutenant-General Khehla John Sitole as national police commissioner on Wednesday was a continuation of his "lamentable record of failing to elevate uncompromised candidates for the job", DA MP Zak Mbhele said on Thursday.
The DA was, therefore, calling for the pending appointment of a new Hawks head, currently filled by acting head Yolisa Matakata, to be more transparent.
"Mbalula is on record that he is finalising the appointment process for the Hawks head," Mbhele said in a statement.
"The lack of a transparent and independent process to date warrants a serious cause for concern that the decision will once again be taken behind closed doors against unknown criteria," he said.
Police ministry spokesperson Vuyo Mhaga said the process to appoint a new Hawks head was still ongoing and there was no new information on the matter.
Mhaga said a date had not been set for the appointment and he could not say if it would take place before the end of the year.
The DA is concerned that Sitole reportedly provided African National Congress presidential hopeful Nkosazana Dlamini-Zuma with a blue lights brigade during her campaign.
'Grown through the ranks'
"If the appointment [of the new Hawks head] is as imminent as Mbalula has indicated, the shortlist must already have been drawn up.
"The only hope for tackling crime effectively is having fit-for-purpose police management, and the appointment of a competent and experienced senior career police officer as the Hawks Head will be vital to turning the tide against organised crime."
The Presidency on Tuesday said that Sihole's appointment was with immediate effect.
"His extensive experience in the police service will assist him to execute this critical task of making South Africans and everyone in the country safer and to feel safer. We wish General Sitole all of the best as he assumes his new position at the helm of a very important institution in government and the country," Zuma said.
Sitole had "grown through the ranks" of the police, Zuma said, joining the service as a constable in 1986 and being promoted to lieutenant-general in 2011.
The position of commissioner has been filled by two permanent appointments and two acting appointments since Jackie Selebi was replaced in July 2009.
Both former permanent police commissioners Bheki Celi and Riah Phiyega were replaced before their terms expired, while acting police commissioner Khomotso Phahlane was replaced after allegations of corruption earlier this year.
Lieutenant-General Lesetja Mothiba had acted in the position since June.