A huge posse of more than 30 dope control officers (DCO) from the NADA have descended here for sample collection from the athletes taking part at the National Inter-State Championships, the final Olympics qualifying event, and they have been instructed to do target testing also.
Usually, dope samples of the medal winners are also collected at big events like the national championships, and the unprecedented number of DCOs present at the Tau Devi Lal Stadium is expected to lead to a large sample size.
The DCOs have mostly come from New Delhi where the National Anti-Doping Agency head office is located.
"I can't tell much, but we have a big team here because it's the most important domestic event of the year as it's the final Olympics qualifying event in athletics," one of the officers, who can't be named for obvious reasons, told PTI on Thursday.
"We are also doing target selection of athletes for collection of samples. That much I can tell."
Even athletes who finished third or below at the heat races in the morning session of the opening day on Thursday were seen being asked by the DCOs to sign the receipt of notification form and agreement to undergo the test.
The NADA team landed here on Wednesday, a day before the start of the championships.
A source also said there was out-of-competition collection of samples, which would mean that it was done on Wednesday.
The officers refused the divulge the exact or the possible sample size.
Meanwhile, 100m national record holder Manikanta Hoblidhar of Karnataka made a shock exit in the preliminary round after finishing fifth in his heat race with a time of 11.10 seconds. His national record stands at 10.23s.
Gold medal contenders Gurindervir Singh of Punjab, Amlan Borgohain of Assam and Animesh Kujur of Odisha won their respective heats easily to make it to the semifinals.
In the women's 100m, Assam's Hima Das, who is yet to attain full fitness after an injury, finished sixth in her heat with an unimpressive time of 12.69 seconds.
The men's and women's 400m races saw a depleted field as some of the top runners pulled out to concentrate in the mixed 4x400m relay race in which India is hoping for a last minute qualification for the Paris Olympics.
The initial entry list had the likes of Jyothika Sri Dandi, Subha Venkatesan and MR Poovamma among women and Muhammed Anas Yahiya and Amoj Jacob but they did not run the individual quarter-mile event.
But still, Kiran Pahal of Haryana stole the limelight in the women's 400m preliminary round with the fastest time of 52.33 seconds.
In men's high jump, national record holder Tejaswani Shankar and Sarvesh Kushare made the finals after finishing first and second in the qualifying round with identical heights of 2.10m.
