Police have questioned Olympic boxer Vjender Singh in connection with a major drug seizure in India’s northwestern state.

Punjab police seized a total of 26kg (57lbs) of heroin, with a street value of 1.3 billion rupees ($24 million) from a flat in Mohali town on Friday and arrested six men, including a Canadian-based Indian, the BBC reports.

The Olympic-bronze medalist’s name had come up during investigations following the arrest of Anoop Kahlon, a non-resident Indian, who is named as the main suspect.

Kahlon claimed he sold drugs to the boxer, a charge which Singh has denied.

But Singh’s sparring partner, Ram Singh, told The Indian Express that they bought drugs from Kahlon and said that they were not habitual users. The national-level boxer had been expelled from the National Institute of Sports after admitting to consuming contraband.

Singh denied knowing any of the men held in connection with the case although reports claim that his car was recovered near Kahlon’s house.

However, the boxer refused to give his blood and hair samples for forensic testing as part of the probe, according to police.

Union Sports Minister Jitendra Singh on Monday said that appropriate action will be taken against the Olympian if he is found guilty in the drug scandal that has rocked Indian boxing, India Today reports.