"He needs to be candid and quite truthful about these sexual
allegations still because people are kind of hesitant a bit to delve
right in there as supporters, not knowing what the truth is," said
Palin on Fox News Channel's "On the Record with Greta Van Susteren"
"It really sucks to be falsely accused — believe me, I know, because I have been also," she added.
Palin drew comparisons between the allegations raised against Cain and media reports that she and her husband had extramarital affairs.
"Once a bell is rung, it's really tough to un-ring it," Palin said.
Palin told Fox News that if the allegations turn out to be true she would not support his candidacy.
"At this point people they don't really want to prejudge because there's still so much speculation and there still isn't a lot of proof really on one side or the other," Palin said.
Cain's campaign has been embroiled in controversy since reports surfaced earlier this month that two women received financial settlements after raising complaints of harassment against Cain while he was the head of the National Restaurant Association in the 1990s.
A third woman, Sharon Bialek, publicly described what she said was an unwanted sexual advance by Cain. The fourth woman to have leveled sexual harassment accusations has remained anonymous.
Cain has said repeatedly that he has never acted inappropriately toward anyone.
"The American people deserve better than someone being tried in the court of pubic opinion, based on unfounded accusations," said Cain last week during his first public presidential debate following the allegations.