Christian evangelical groups in the US are attempting a "cultural colonisation" of Africa, opening offices in numerous countries to promote attacks on homosexuality and abortion, according to an investigation by a liberal thinktank.

American religious organisations are expanding their operations across the continent, lobbying for conservative policies and laws and fanning homophobia, argues the Boston-based Political Research Associates (PRA).

The groups include the American Center for Law and Justice (ACLJ), founded by the televangelist Pat Robertson, which has established bases in Kenya and Zimbabwe.

"The religious right [in effect] claims that human rights activists are neocolonialists out to destroy Africa," the report states. Groups named in it vehemently rejected the claims.

Entitled Colonising African Values: How the US Christian Right is Transforming Sexual Politics in Africa, the study analysed data from seven African countries and employed researchers for several months in Kenya, Malawi, Zambia and Zimbabwe.

It identified three organisations it believes are aggressively targeting the continent: Robertson's ACLJ, the Catholic group Human Life International and Family Watch International, led by the Mormon activist Sharon Slater.