The Panel imposed a sanction of two-year ban on Muralidharan, starting October 25, a NADA source told PTI.
"Arjun has been handed a two-year ban. He can appeal to National Anti-Doping Appeal Panel," the source said.
26-year-old Maharashtra swimmer Muralidharan has won 15 national titles so far. He at one point of time held the national records in 50, 100 and 200 meter butterflies simultaneously. He has also been the best swimmer in three consecutive Open National Championships from 2004-2007.
His brother Amar Muralidharan was also handed a two-year ban by the same panel in November last year after testing positive for the same stimulant, Methylhexaneamine.