Could the illegal shooting of a moose in the Alaskan wilderness affect the outcome of the race for the White House?

Alaska's lawmakers were last night reviewing a potentially explosive report after their investigation into charges that Sarah Palin abused her power as Governor by sacking a senior official because he refused to bow to her wishes in a vendetta against her estranged brother-in-law.

The report's focus is on the sacking in July of former Alaska public safety commissioner Walter Monegan. Mr Monegan, who ran the state police force, claims he was ousted because he refused to sack Mike Wooten, the ex-husband of Mrs Palin's sister. One of the complaints given by Ms Palin's aides against Mr Wooten was that he pulled the trigger that felled a moose without a licence.

The findings could wreak havoc with John McCain's already faltering presidential hopes by reopening questions about his failure to vet his running mate. There is even a possibility of a criminal investigation into Mrs Palin. A scandal would, at best, be an unwelcome distraction for Mr McCain in the crucial final weeks of the election. The inquiry added to claims that Mr McCain is erratic at a time when steady leadership is needed.

The bipartisan investigation began before Ms Palin was picked as John McCain's running mate. Mrs Palin, who did not co-operate with the inquiry, denies any wrongdoing. Her critics allege that she wanted Mr Wooten drummed out of the police force on technicalities including that he illegally killed a moose during a family hunting expedition in 2003 when he was still married to her Ms Palin's sister, Molly. Molly had a hunting licence but her husband fired the fatal shot and the animal was eaten by the entire extended Palin family.

The tensions with Mr Wooten appear to long predate Sarah Palin's ascent to the governorship. After Mr Wooten had a bitter custody battle with Molly in 2005, Mrs Palin wrote a three-page email to Colonel Julia Grimes, who was then head of the state police force, accusing Mr Wooten of threatening to murder her father, driving on duty while drunk, using a stun gun on his 11-year-old stepson, shooting the moose without a permit, failing to pay a $5 fine for improper rubbish disposal, using illegal steroids and drinking while in his patrol car"

"Wooten is my brother-in-law, but this information is forwarded to you objectively," Mrs Palin wrote.

Todd Palin, although a private citizen whom the Governor refers to as the "First Dude" is accused of hounding officials to have Mr Wooten sacked.

He acknowledged this week in testimony to the inquiry that he made phone calls and convened meetings claiming Mr Wooten was a dangerous, unstable man who had threatened his family and should be dismissed. He said he made "no apology for wanting to protect my family". At one meeting in January 2007, according to the New York Times, the Governor's husband showed Mr Monegan pictures of the dead moose.

A subsequent inquiry found Mr Wooten guilty of "unacceptable and at times illegal activity". He was given a five-day suspension and warned he would be dismissed if he offended again.

The case, known in Alaska as "Troopergate", would never have exploded into the race for the White House if the matter had been allowed to rest at that.

But Mr Monegan claims the pressure on him to fire Mike Wooten intensified after the suspension. Mrs Palin denies instructing Mr Monegan to sack Mr Wooten and claims she sacked him over policy differences.

Earlier, the McCain campaign gave its version of events, portraying the argument as a legitimate policy dispute and political event. "The following document will prove Walt Monegan's dismissal was a result of his insubordination and budgetary clashes with Governor Palin," the campaign said.

As the lawmakers met yesterday, Palin supporters wearing clown noses and carrying balloons greeted them with cheers that "the circus is in town".

Mr Monegan said: "I just hope the truth is fgured out. That the governor did want me to fire Mr Wooten and I chose not to. You just can't walk up to someone and say, 'I fire you'. He didn't do anything under my watch toresult in termination."