Dank, the former Essendon sports scientist at the centre of the scandal, said on Monday a number of coaches were using supplements that would have been illegal for their players to use.
"There were some differences obviously in what we offered the coaches. Let's face it, the coaches themselves are not subjected to any WADA code," Dank told ABC's 7.30.
"It may have been three, four, maybe five were taking vitamin supplements, protein supplements. To be perfectly honest there were a couple of coaches who were using supplements, if you like, that were a little bit outside the WADA code, but again they were entitled to it, nothing illegal there."
But Ings, the chief executive and chairman of ASADA from 2006-10, said the investigators would closely follow up Dank's allegations.
"[The interview] certainly answered a lot of questions, but unfortunately it raised as many questions as it answered and ASADA is going to have its work cut out getting to the bottom of this," Ings told SEN radio.
"This is a very, very complex and unprecedented situation and I'm sure ASADA will be dissecting that video very carefully and talking to all the key parties involved."
Although Dank denied any use of prohibited supplements by Essendon players, Ings said the "troubling" claim on coaches would have ASADA digging deeper.
"Because ASADA at the end of the day is an investigative body and they're trying to follow the trail of performance-enhancing drugs to see whose hands they went through," Ings said.
"ASADA will be piecing this together step by step."
