Keith Morris, 72, from Hull, carried out the crimes while on holiday in a remote village between 2016 and 2017, the National Crime Agency (NCA) said.
He denied 13 charges including rape and sexual assault but was convicted following a trial at Leeds Crown Court.
The Crown Prosecution Service (CPS) said he befriended the young victims’ families over the past 20 years, giving them money and gifts.
Morris, a retired locksmith of New Bridge Road, also financially sponsored several of the families, providing household goods, clothing, medical treatment and paying for their children’s education, the CPS said.
He would take groups of children out of the village for day trips and would buy them sweets, make-up, meals out and often invited them to stay in his hotel rooms.
The NCA said it was during these trips he had abused the children.
An investigation was launched after a hotel guest raised concerns, the CPS said.
He was arrested in February 2017 and during a search of his home, officers said they found a Dictaphone containing audio recordings of phone conversations in which he had asked his victims “to sign retraction statements stating the sexual abuse had not occurred”.
He also transferred money to associates in Kenya in exchange for help to prove his innocence, the NCA said.
The CPS said it had arranged for one of his victims to give evidence at his trial from Africa via video-link.
Morris was convicted of four counts of rape, three counts of assault by penetration, four counts of sexual assault and two counts of perverting the course of justice.
He is due to be sentenced in Leeds on 17 July.
By Africafrique and agencies