* Says coal dust levels were not excessive
* Says blast contaminated dust samples
NEW YORK Jan 28 (Reuters) - Massey Energy Co MEE.N said federal investigators' claims that excessive coal dust fueled a deadly explosion at its West Virginia mine last year were based on faulty data.
Instead, the explosion that killed 28 miners last April spread the coal dust at the mine, Massey general counsel Shane Harvey told reporters on a conference call on Friday.
An inspection less than three weeks before the accident did not detect the coal dust in the quantities the federal investigators found after the blast, he said.
"We think that the explosion effects contaminated the samples," he said, referring to the hundreds of tests conducted by investigators at the mine after the disaster.
The April 5, 2010 explosion at the Upper Big Branch Mine in West Virginia was the deadliest mine accident in the United States in 40 years, and prompted the resignation of the company's chief executive, Don Blankenship, in December.
Officials from the Mine Safety and Health Administration said last week that high levels of coal dust helped fuel the blast, which it believe was ignited when sparks from a rock shearer reached a methane leak.
Harvey reiterated Massey's belief that the explosion happened because of a natural gas leak from a crack in the mine floor rather than methane, which is much more common in coal mines.
He also disputed MSHA's allegations that sprinklers on the rock shearer were not in working order, and that the teeth on the machine were too worn down and created too many sparks.
Shares in Massey were up 1.2 percent, or 65 cents to $55.04 per share on the New York Stock Exchange ,and slightly below the 27-month high that they reached last week. (Reporting by Matt Daily. Editing by Robert MacMillan)