India\'s hopes of a coveted track medal at next year\'s Olympic Games in London have taken a hit after two of the country\'s Commonwealth Games and Asian Games gold medallists failed drug tests. The National Anti-Doping Agency (NADA) said that women\'s 4x400m relay runners Mandeep Kaur and Sini Jose tested positive for banned steroids and were suspended pending the results of their B samples, due in the coming days. NADA director-general Rahul Bhatnagar told AFP that the findings -- among six positive tests for steroids on Indian athletes in recent days -- made it unlikely that either would compete in the British capital. \"Because they\'ve reached national level, they\'ve been tested hundreds of times. It\'s not that they\'re not aware (of banned drugs),\" he said. \"With steroids I\'m doubtful if they would get a reprieve. If they\'re banned for two years, they won\'t get a chance to compete in the Olympics.\" Hopes have been high in India for its women\'s 4x400m relay team since winning the country\'s first-ever women\'s Commonwealth Games track gold in front of home fans in New Delhi last October. They repeated their success in November at the Asian Games in Guangzhou, China. Kaur and Jose were part of both winning teams. Kaur protested her innocence, telling the NDTV news channel: \"I have full faith that I did nothing wrong. I don\'t understand what\'s happened. There could have been problems with food supplements or minerals that we have taken. \"I\'m not mad enough to take steroids, which remain in the body for months... I\'m not giving up. I will practice for the Olympics... I will prove to others that I am innocent,\" she added. India has never won a track medal at the Olympics and just missed out in Los Angeles in 1984, when P.T. Usha narrowly failed to take a bronze in the women\'s 400m hurdles. Milkha Singh was also edged into fourth in a photo-finish in the men\'s 400m in the 1960 Rome Games. Bhatnagar said two other female 400m runners, Tiana Mary Thomas and Jauna Murmu, plus a female shot-putter, Sonia, also tested positive. The Times of India newspaper on Friday said all four one-lap specialists were trained by the same Ukrainian coach. \"It\'s the samples of the athletes that\'s tested positive,\" said Bhatnagar. \"There\'s no evidence that the coach had a role but if we get information that the coach was involved in this then the coach can also be suspended.\" Kaur, Jose, Thomas and shot-putter Sonia tested positive after a national track meet in the southern city of Bangalore late last month. Murmu and leading Indian male long-jumper Hari Krishnan Muralidharan, who also gave a positive sample, were tested out of competition. India\'s anti-doping agency regularly conducts sessions with Indian athletes to inform them about banned substances. The acting president of the Indian Olympic Association, V.K. Malhotra, said there should be \"exemplary punishment\" for any athlete found guilty. \"The winning of medals at the cost of shame to the entire nation is not proper,\" he told NDTV. Doping has afflicted Indian sport over the last decade, with weightlifters being the chief culprits. Seven Indian athletes -- four wrestlers, a shot-putter and two swimmers -- were suspended for taking the banned stimulant methylhexaneamine in the run-up to the last Commonwealth Games. Their suspensions -- and those of four others who failed tests but were not picked for the Games -- were lifted after the World Anti-Doping Agency (WADA) re-classified the stimulant, allowing them to compete. During the Games, an Indian athlete competing in the women\'s 20km walk tested positive for the banned substance nandrolone.