India’s weightlifting boss vowed Friday to fight a doping suspension against Commonwealth Games double gold medallist Sanjita Chanu, who is facing a four-year ban.

The International Weightlifting Federation said the 24-year-old Chanu, who won gold in the women’s 53kg class at the Commonwealth Games in Australia in March, had tested positive for the anabolic steroid testosterone.

Chanu is the 13th Indian weightlifter to test positive in IWF tests in the past decade. But the Indian Weightlifting Federation said it would fight the case of the lifter, who also won the 48kg Commonwealth gold in Glasgow in 2014. Federation secretary general Sahdev Yadav said Chanu, who was provisionally suspended, failed the test before last year’s world championships in the United States. India was only told on May 15.

“We don’t understand why the dope result took so long,” Yadav told Press Trust of India news agency. “We will fight it out.”

He said the Indian federation would demand a new test. “After we get the results we will hire a top lawyer to present our case at the hearing. “I am sure Sanjita has not taken any banned drugs. I am confident we will prove her innocence,” he added.

Chanu was one of five weightlifters whose suspensions were announced late on Thursday by the IWF. They included Witoon Mingmoon of Thailand, who won the men’s 56kg bronze medal at the world championships.