"She could go into hiding in her own country and have the ability to take drugs because they can't get there to test her.
"On the surface, it looks like she could do that for the next 18 months, come off the drugs, compete the week after Rio and break the world record. I don't think that would be good for anyone involved and I'm going to start the process of trying to get some answers around that.
"Is she going to be on a testing regime? Is she going to be on a whereabouts programme? If not, why not?"
Cowan will approach Athletics New Zealand and Drug Free Sport NZ chief executive Graeme Steel and petition them to voice their concerns.
"We have good relationships with the governing organisations in this country and I intend to work with them," Cowan said.
There are concerns in the wider athletics community about the robustness of the Belarussian drug testing programme.
Adams' coach Jean-Pierre Egger famously questioned Ostapchuk's rapid progress in the leadup to London, especially given her lack of activity on the competition circuit, with his loaded "prefer to keep silent" statement on the night Ostapchuk won gold in London.
The chance to appeal against the length of Ostapchuk's ban has passed - this could have been done by only Wada, the IAAF and the Belarus athletics federation - and Wada boss David Howman said they dismissed the idea because the ban was consistent with guidelines.
Ostapchuk will be 35 when her ban expires in 2016 and it's questionable how competitive she will be if she returns to competition.
"I don't see her as a threat at all if she's subject to normal athlete testing regimes," Cowan said.
"This has no impact on our planning in the next five years but, because of what has happened in the past, that raises concerns."