Both sisters have been the subject of dispute about their sex, with Nigeria and Ghana raising official complaints with CAF over the last two African Women Championships.
Both players were key as the country won the 2008 tournament which they hosted, and reached the Final of the 2010 tournament in South Africa where they lost to Nigeria.
Salimata was also accused of having played for both Burkina Faso and Ivory Coast before.
A number of the Nigerian players had complained that the speed and strength of both players was more than the average girl.
Fifa have recently introduced a gender testing protocol, although it insists that "No mandatory or routine gender testing verification examinations will take place at Fifa competitions".
However, an independent expert has been appointed to ensure compliance at this month's Fifa Women's World Cup.
Fifa said each association will have to ensure gender compliance or face sanctions in the event than another association lodges a complaint and a case is proven.
"It lies with each participating member association to prior to the nomination of its national team ensure the correct gender of all players by actively investigating any perceived deviation in secondary sex characteristics and keeping complete documentation of the findings."
It is not clear if a failed test is the reason for Equatorial Guinea withdrawing two of its best players.