The International Association of Athletics Federations on Monday said it was freezing all new transfers of allegiance, with IAAF president Sebastian Coe saying that the "present rules are no longer fit for purpose".
Kenya has suffered particularly badly: since 2003 more than 60 Kenyan-born athletes have given up their nationality to run for another country, most notably for Bahrain and Qatar.
During the Rio Olympics, 20 former Kenyans competed for adopted countries, including Ruth Jebet, who upset her former compatriots to win the first Olympic gold medal for Bahrain in the 3,000m steeplechase.
Wambua, also a member of an Athletics Kenya (AK) youth committee, said many under-age children were transferred to other countries without their say-so, often after their parents were "enticed" with money.
More From This Section
"The change of allegiance has been a big blow to this country. Some of our innocent children have been lured away without their knowledge by people masquerading as their coaches, managers and agents.
Wambua said Kenya had no problem with any athlete trying to earn a living by competing for another country but they must only do so when they are old enough and given clearance by the national federation.