Those in favour of the deal said it could help improve ICBP's financial performance.
Indonesian rules do not automatically block related parties from voting. ICBP is 80% owned by Indofood, which is controlled by First Pacific.
ICBP's shareholder vote, scheduled for Wednesday, was postponed because Indonesia's financial regulator said it needed to give shareholders additional information, according to announcements in local newspapers.
Such interventions from the regulator are unusual.
"The question is whether there would be a difference in price if ICBP had to convince their minorities," said Zamorano.
Independent valuations cited by ICBP to its shareholders were in line with and higher than the eventual price tag.
Chris Leahy, founder of corporate advisory firm Blackpeak, said the valuation seemed high but not shockingly so.
"This is a really good example of how weak the related party transaction rules are in Indonesia," he said.
A spokesman for First Pacific directed Reuters to a letter recommending the transaction by the independent financial adviser to the independent shareholders. ICBP did not respond to a request for comment.
A spokesman for Axton Salim, Anthoni’s son and a director of ICBP and also First Pacific, declined to comment. Anthoni Salim could not be reached for comment.