The World Anti-Doping Agency warned the Olympic Council of Asia of "consequences" on Friday for allowing the North Korean flag to be repeatedly flown at the Asian Games, saying they were treating it "extremely seriously".

WADA declared North Korea's national anti-doping body "non-compliant" in 2021 and imposed sanctions that remain today.

They include not being able to fly its flag at any regional, continental, or world sports event, excluding the Olympics and Paralympics.

Despite this North Korea carried the flag at the Asian Games opening ceremony and it has been routinely hoisted in Hangzhou when their athletes won medals.

OCA chief Raja Randhir Singh last week defended allowing the North Korean flag to be flown, saying the governing body of the sport in Asia had written to WADA "explaining their position".

In a statement to AFP, WADA said the OCA had breached its obligations as a signatory to its anti-doping code.

"WADA takes this matter extremely seriously and has written to the OCA on several occasions before and after the opening ceremony of the Games, explaining in clear terms the possible consequences that could arise for the OCA if this matter is ignored," it said.

"WADA is disappointed that the OCA has to date not taken steps to comply with the terms of the DPRK's non-compliance," it added, using an acronym for North Korea.

"WADA will follow due process to ensure that the appropriate consequences are imposed for the OCA's refusal to meet its signatory obligations."

There are a range of punishments WADA could impose on the Kuwait-based OCA.

They include having International Olympic Committee (IOC) funding withdrawn, OCA events losing their status as qualifying events for the Olympic or Paralympic Games, and the imposition of fines.

OCA declined to comment when approached by AFP.