The gold miner announced Olena Dorati as owner of the Cyprus-registered CABS but said she was not the one pulling the strings.
Petropavlovsk did not find a name attached to Slevin, but said the Anguilla-registered investment body was owned by Redlands Capital Holdings, a British Virgin Islands-registered company.
The announcement came days after senior operating subsidiary managers inside Petropavlovsk wrote to the board and shareholders backing the former CEO Pavel Maslovskiy's return to the company and the sacking of all current directors.
Sir Roderic Lyne and Robert Jenkins would also join the board under the CABS and Slevin shareholder requisistion, which will be voted on at the annual general meeting on June 29.
That group and its representatives have so far refused to identify the people behind the shareholder machinations.
It's possible they will succeed with major holder Kenges Rakishev supporting the shake-up, getting them more than 30% support.
Petropavlovsk said the names revealed little about the beneficial holders of the combined 9.1% stake in the company.
"The board considers that this is just another level of cascading shell companies being used by the mystery owner and that there may be several further layers before the true identity of the respective controlling persons are disclosed," the company said.
"The board sees no sign yet of a decision-maker with the requisite experience in the gold mining sector to make the claims in the requisition, the financial resources to set this scheme up, or the required expertise to formulate a strategy that will deliver returns for all shareholders."
Petropavlovsk had reportedly previously gone to UK regulators about the identity cover-up, but Sir Roderic said they were happy to talk to listing authorities.
In ithe announcement of the names behind CABS and Slevin, Petropavlovsk said the motivations of those trying to sack them had to be questioned.
"The board has noted what seems to be the extraordinary lengths taken by the mystery owner in hiding the identity of the beneficial owners from the rest of the company's shareholders and can only assume that there are material reasons for doing so," the company said.
Companies House lists three past directorships for Dorati; Blomwood Ltd, Agroresources Ltd and Silver Order Ltd.
Only Silver Order is still active, but she resigned as a director in 2013.