US lawyer James Cameron Jr and UrAmerica chairman Damien Hackett will join the miner's board five months after Pavel Maslovskiy, Sir Roderic Lyne and Robert Jenkins received the backing of a mysterious group of shareholders and took back control of the company.
The board grew to four once Kenges Rakishev's representative Bektas Mukazhanov rejoined in July.
Sir Roderic said the new board members brought Russia experience (Cameron) and London finance know-how (Hackett).
"Jim Cameron is well known in business circles in California as a successful entrepreneur and investor and has had wide experience in Russia over the past quarter-century, including as an adviser to gold-mining projects in the Far East of the country," he said.
"Damien Hackett has been involved in the mining sector since 1975 as a geologist, analyst and investment adviser, and has known Petropavlovsk well over the past 15 years.
"These new appointments, resulting from an extensive process assisted by the recruitment consultants Savannah, mean that Petropavlovsk now has three independent directors with a diverse range of skills and experience of great benefit to the company."