An Australian pension fund group has called on its members to vote to remove several News Corporation board members, including James and Lachlan Murdoch, in order to ensure the independence of the board.

The Australian Council of Superannuation Investors, which represents pension funds that manage A$250 billion ($244 billion) in assets, said in a statement that investors should vote against the two sons of chief executive Rupert Murdoch, and three other executives who have each served at least 20 years on the board due to their perceived close links to the founder.

The annual shareholders' meeting is on October 21.

The council's Chief Executive Ann Byrne said the phone hacking scandal at News Corp brought into question the effectiveness of oversight and risk management at the media organization.

Responsibility for this, as well as setting the ethical tone throughout News Corporation and affiliated organizations rests with the News Corporation Board, Byrne said.

She said a clear message needed to be sent to the board, even though there was little prospect that the current directors would be voted down at the upcoming shareholders' meeting.

A Murdoch family trust controls about 40 percent of the voting shares.

A spokesman for News Corp's Australian arm, News Ltd, could not be immediately reached for comment.

(Reporting by Victoria Thieberger; Editing by Ed Davies)