Marth's body was found in his Las Vegas-area home Monday morning, the office told E! News Thursday.
No other details regarding the manner and circumstances of his death were immediately reported.
"Last night we lost our friend Thomas Marth. Our prayers are with his family. There's a light missing in Las Vegas tonight. Travel well, Tommy," his band mates said in a statement posted on the band's Facebook page and Twitter Monday.
E! News said Marth is survived by his parents and two siblings. He was a member of the band since 2005.
Celebrity Families of 2014 [PHOTOS]