The policy concluded by calling for Canada to overhaul its divorce laws and adopt the "equal parenting" principle in custody battles.
This principle would set 50/50 custody as the default result of divorce settlements, as opposed to the current system which gives judges more discretion based on "the best interests of the child."
Men's rights groups are typically at odds with feminist groups and the left-wing bases of parties like the Greens. When the page was raised on Twitter this week, users accused the party of having a divorce policy based on MRA ideology.
May went to Twitter to refute the policy. She said it was no longer the party's official policy and the Greens do not advocate for blanket 50/50 custody.
Between Tuesday evening and Wednesday morning the party slashed its policy statement down by more than half - from 616 words to 299 words.
"It certainly doesn't reflect what the party believes in," said party spokesman Julian Morelli.
"Unfortunately that was an error, and it was fixed.
Morelli said the party was grateful to the public for raising the issue so they could correct it. He said he did not know how the policy was developed or how it came to be put on the party's website.
It's not clear how long the policy was online. The only archived snapshot of the old policy is from earlier this month, on August 7.
The party erased sections condemning no fault divorce laws and the section calling for an equal parenting system. They also removed claims of rampant false allegations.
The new policy emphasizes that the best interests of the children to be at the core of settlements. But it still calls for current laws to be changed.
The revamped policy says the court system is dysfunctional (which is shortened from the original wording of "dysfunctional and arbitrary") and is eroding "the very fabric of Canada."