Congolese and foreign activists on Monday called on Pope Francis to sanction a priest accused of sexually abusing a minor in the Democratic Republic of Congo where he arrives on Tuesday.

A girl identified as Marie told reporters by video conference how she was raped nearly two years ago by a priest from the Tshumbe diocese in the centre of the country, when, at the age of 14, she was "aspiring" to join the church.

Marie said she had informed the church authorities in Congo.

Since then, "I am not living in safety, everyone around me is under threat," she said.

"It's a serious case," Tim Law, founder of Ending Clergy Abuse (ECA), told a press conference in Kinshasa, where his NGO is seeking to give a voice to victims of sexual abuse by members of the clergy.

"It's your duty to protect the children" from "the lies of pastors", he said alongside members of Come, a Congolese association fighting sexual abuse.

"Pope Francis, the youth are counting on you because living in poverty, they are at the mercy of predators," Law said.

Victims had to be respected, not punished, he added.

A church source told AFP "the Holy See has sent investigators, the priest (facing the allegations) has been suspended and the case brought before Congolese justice".

The Vatican probe found no evidence and the justice system "exonerated" the priest who has been "rehabilitated" the source added.

Marie's lawyer Come Musuluku said she had fled to Gabon, but intended to appeal the Kinshasa court decision.

Rocked by thousands of reports of sexual abuse around the world by priests and accusations of cover-ups by senior clergy, Pope Francis vowed an "all-out battle" against paedophilia within the Church in 2019.

He has lifted secrecy rules that discouraged the reporting of abuse, obliged those who know about sex abuse to report it to their superiors and streamlined the Vatican office that processes complaints, among other measures

Pope Francis embarks on his fifth visit to Africa on Tuesday, flying to the Democratic Republic of Congo and then on to South Sudan, carrying a plea for peace.