Ugandan police have launched a probe into allegations that two orphanages are involved in child trafficking.
There are few figures about human trafficking in East Africa
Police Inspector General Kale Kayihura made the disclosure at a media briefing during a conference to look at fighting human trafficking in East Africa.
Ugandan academic Moses Okello told the BBC that a spate of recent cases showed the scale child trafficking in Uganda "could get out of hand".
He blamed porous borders and lax immigration controls for the problem.
"There is a local joke here that it's quite difficult to pass drugs through the Ugandan immigration ports, but it's easy to pass humans," said Mr Okello, who runs the Refugee Law Project at Makerere University.
He told the BBC's Focus on Africa programme that Uganda had fairly progressive child-protection provisions, but lacked resources to implement them.
"I can totally understand why border controls can be very problematic for the immigration officials - given that quite a lot of them are not skilled enough to understand or even to detect how child-trafficking rings operate," he said.
"Besides, Uganda's naming system is so fluid that anybody could pass off as being the parents of a kid."
In the last couple of weeks, some Ugandan children had inexplicably ended up in Kenya without any parental protection, he said.
"We also know that from our legal aid clinic here [that] there are quite a bunch of people who have showed up in the last month claiming to have been trafficked or to know people who have been trafficked."
Correspondents say little is known human trafficking in East Africa and the conference in Uganda's capital, Kampala, hopes to come up with an action plan to address the lack of information and find ways to curb it.