But on Wednesday Fairfax chairman Roger Corbett knocked back a request from Mrs Rinehart's for a board seat, saying the board could not reach agreement with her on the issue of Fairfax's charter of editorial independence and other board governance principles.
Existing directors are keen for her to sign a charter of editorial independence before any offer of a board position is made.
"It's got a minimum of another six months to play out, but I suspect she'll end up with the lot if the shareholders lose confidence," Mr Peters told AAP.
He added that it would be unacceptable for Ms Rinehart to threaten to sell her shares if she was not given board seats.
"Someone's obviously drafted it (the statement) so that the Fairfax directors sit back and say, wow, she'll be back," Mr Peters said.
"It implies that (Fairfax) is facing annihilation and I'm here to save you.
"It does not say how this help may be delivered."
When any person buys shares in a company they were buying into the current arrangements, he said.
Any substantial new shareholder is entitled to ask for a seat on the board, but if they are knocked back they can ask the shareholders for this privilege.
If the corporate regulator, the Australian Securities and Investments Commission (ASIC), pursued the case, Mrs Rinehart could argue that Fairfax had refused her help as a major company restructure takes place.
Fairfax recently announced a major restructure involving the loss of 1,900 jobs, slimmed down metro newspapers and a heavy focus on digital publishing.
ASIC needs to consider whether Ms Rinehart's actions will benefit the company as a whole.
However, it's understood that at this stage ASIC is not concerned by Mrs Rinehart's statement.
Analysts say Mrs Rinehart could effectively take control of Fairfax with a stake of more than 25 per cent.
But under corporations law and continuous disclosure rules, it would be difficult to prove that the share price had been driven down prior to a takeover offer.
It's also unlikely that minority shareholders would pursue a class action against a Hancock Prospecting takeover because cash would be a more attractive result than litigation.
A capital raising was also unlikely.
An ASIC spokesman said the regulator had no comment about the case.
A Hancock Prospecting spokesman was unavailable for comment.
- AAP