(Reuters) - JKX Oil & Gas Plc, whose second-largest investor is seeking a board shake-up, said it had issued notices to two of its top shareholders, restricting them from attending or voting at a general meeting later this week.
JKX said it had taken the action against Eclairs Group Ltd and Glengary Overseas Ltd after enquiries into the ownership structures and voting arrangements relating to their respective 27.47 percent and 11.42 percent interests had "not been able to ascertain full and accurate particulars".
Eclairs is controlled by trusts associated with prominent Ukrainian businessman Ihor Kolomoisky and his associate Gennadiy Bogolyubov, according to a UK Supreme Court document.
A spokesman for Eclairs, JKX's largest investor, declined to comment.
Glengary is controlled by Alexander Zhukov, according to the court document. Reuters was not immediately able to contact Kolomoisky, Bogolyubov or Zhukov.
Shareholders in JKX are due to vote on Thursday on proposals by Proxima Capital Group Inc, which is seeking the removal of seven of JFX's nine directors, including its chairman, chief executive and finance director.
JKX has had a tumultuous few years, hurt by low oil prices and growing political tensions between Russia and Ukraine, its two main markets. Its shares have tumbled more than 90 percent over the past five years.
The company has repeatedly called on shareholders to reject the proposals by Proxima, which owns nearly a fifth of JKX. The company's position has been backed by shareholder advisory firm Institutional Shareholder Services.
"We are not privy to the detailed reasoning of how the board of JKX have come to their decision to disenfranchise shareholders representing nearly 40 percent of the ownership of their company," Proxima CEO Vladimir Tatarchuk said in an email.
"We call on the JKX board to ensure that all shareholders are given the opportunity to vote on critical issues affecting the company's future."
Eclairs spearheaded its own revolt against JKX's board in 2013. At the time JKX suspended its right to vote at general meetings and restricted its right of transfer. Eclairs was ultimately unsuccessful in its attempt to remove JKX CEO Paul Davies, who has been on the board since 1998.
Proxima has had no restrictions imposed on it and intends to vote, a company spokesman said.
Editing by Sunil Nair and Alexander Smith