Republican vice-presidential nominee Sarah Palin abused her powers as governor of Alaska, a state investigator's report released on Friday said.
The report concludes an investigation into whether Palin fired the chief of Alaska's police force after he refused to get embroiled in a family feud.
The probe started before Republican presidential candidate John McCain picked Palin as his running mate in August. Dubbed "Troopergate" in the US media, the report surfaces uncomfortably a few weeks before the Nov 4 presidential elections.
Palin is alleged to have fired Alaska's Public Safety Commissioner Walt Monegan after he refused to sack state trooper Mike Wooten, her former brother-in-law who was in an acrimonious custody battle with her sister.
"Governor Palin knowingly permitted a situation to continue where impermissible pressure was placed on several subordinates in order to advance a personal agenda," read a statement from the 263-page report by Stephen Branchflower, a former Alaska prosecutor who conducted the investigation on behalf of the state legislature.
Branchflower concluded that Palin violated Alaska's Executive Branch Ethics Act, which states that "each public officer holds office as a public trust, and any effort to benefit a personal or financial interest through official action is a violation of that trust."
However, the politically-sensitive report also determined that while the family feud was a "contributing factor" in the dismissal, it was not the only reason.
Many Republicans have dismissed the investigation as "politically motivated". Palin supporters gathered outside the meeting venue in Anchorage, dressed up as clowns and carrying balloons and banners as they criticised the hearing as a "kangaroo court" and "three-ring circus."
On Thursday, Palin told reporters that she had "absolutely nothing to hide" in the investigation. She has said earlier that Wooten threatened her family.