WADA said it filed "two separate requests for arbitration with the Court of Arbitration for Sport" in the two cases last week. The two national agencies were sanctioned in November for failing to address what the Montreal-based doping watchdog called a number of "critical requirements" in their anti-doping programmes.

As a result, they lost their rights within the organisation and were banned from hosting major sporting events. Their flags were also banned from being displayed at major competitions, including the Olympic Games, until they met WADA's requirements.

The allegations against them and the proposed sanctions have been contested by both national agencies. The sanctions against them are effectively suspended pending the outcome of the Court of Arbitration. Updates on the arbitration decisions and the potential impact on Nigeria and Venezuela are expected later this year.

Compliance with the anti-doping rules is essential for clean international sport, WADA stressed. In the ongoing cases against Nigeria and Venezuela, WADA will now await the decisions of CAS.