The Office actor Mark York has died at the age of 55 after an undisclosed illness, it has been reported.
According to TMZ, the star, best known for playing Billy Merchant in seasons 1 and 2 of The Office alongside Steve Carell, died last week at Miami Valley Hospital in Ohio.
The exact cause of death has not been revealed, but it is believe he died quickly after the illness surfaced.
Mark grew up in Ohio, but quickly moved to California to pursue acting .
He landed a host of small TV roles such as CSI: New York in 2004 and Fighting Words in 2007.
But his best known role was no doubt on The Office, where he played Billy Merchant. A paraplegic since 1988, one famous scene saw Mark's character brought in for a disability-awareness meeting, run by Steve Carell's character Michael Scott.
More recently Mark had actually been working as an inventor, even securing two patents for his work.
He's survived by his brother, mother and father.
Tributes for the star have begun to flood onto social media, with some fans revealing Billy as their "favourite character".
"Rest In Peace Mark A. York, he portrayed Billy in The Office, one of my favourite characters," one fan wrote on Twitter.
"Very young, may he rest in peace," another wrote.
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