In a 5-4 vote, the high court reversed the lower court’s verdict, which had overturned a verdict that ordered the producer to pay Harman owner Hugh Caperton $US50 million in damages.

Specifically, it said state Supreme Court Chief Justice Brent Benjamin should have excluded himself from the case because of $3 million in campaign contributions to Benjamin that were made by Massey chief executive officer Don Blankenship in 2004.

The donation created “a serious, objective risk of actual bias that required Justice Benjamin’s recusal” because he could not hear the dispute impartially, Justice Anthony Kennedy wrote in a majority opinion.

"We conclude that there is a serious risk of actual bias ... when a person with a personal stake in a particular case had a significant and disproportionate influence in placing the judge on the case."

Caperton’s attorney David Fawcett told various media that they welcomed the ruling.

"While we are disappointed in the outcome of the Court’s close vote, our outlook about the ultimate resolution of this legal matter remains positive,” Massey vice president and general counsel Shane Harvey said.

“We are confident that the Harman case was properly decided by the West Virginia Supreme Court initially, and believe that any new examination of the same facts and same laws by new justices should yield the same result as before.”

One involved group, the United Mine Workers of America, was happy about the decision and called it “welcome news”

"Justice is supposed to be blind, but it was not in this case,” UMWA president Cecil Roberts said.

"This is an important case to the UMWA. The workers at Harman Mining

are our members [and] when Massey put the company out of business, it put our members out of work, with no health care benefits.”

He noted that, for some time, the union stepped in and paid those benefits.

"UMWA members who worked at Harman are owed in excess of $13 million

for past and future health care obligations,” Roberts added.

“They and the union are looking forward to this money being repaid to them, and soon."

In 2002, Massey Energy was ordered to pay $50 million to Harman Mining Corporation after a contractual dispute that began in 1997 and ultimately led to the bankruptcy of Harman.

Harman Mining Corporation launched actions in Virginia and West Virginia against the mining giant, and the Virginia case settled in 2001 with a $6 million judgment awarded to Harman.

Massey Energy lodged an appeal against the West Virginian ruling that "with interest" saw Massey potentially liable for $76 million.

In siding with Massey's appeal in 2007, the Supreme Court agreed the court case settled between the companies in Virginia should have ended the matter, as it was filed for the same dispute.

Massey Energy paid the entire balance of the initial $6 million settlement.