India has suspended steeplechase runner Naveen Dagar after he failed a dope test in a crucial blow to the country's medal hopes at this month's Asian Games, an athletics source told AFP on Friday.

Dagar, who won a bronze at the 2014 Asiad, tested positive for banned meldonium, the source close to the Athletics Federation of India (AFI) said.

The 30-year-old was tested during an inter-state competition in the northeastern city of Guwahati by the National Anti-Doping Agency (NADA).

"Yes, Dagar was suspended on July 23. Meldonium was found in his sample. Though a B Sample report is awaited," the source said.

"It is disappointing because he was a medal hopeful and India will now go unrepresented in the 3,000 metre race."