South Africa has filed evidence of a genocide committed by Israel in the Gaza Strip with the International Court of Justice, the office of President Cyril Ramaphosa said on Monday.

The document "contains evidence which shows how the government of Israel has violated the genocide convention by promoting the destruction of Palestinians living in Gaza", the presidency said in a statement, amid claims vehemently denied by Israel.

An official for the Hague-based court on Monday confirmed it had received the document, but did declined to give further detail.

"The evidence will show that undergirding Israel's genocidal acts is the special intent to commit genocide, a failure by Israel to prevent incitement to genocide, to prevent genocide itself and its failure to punish those inciting and committing acts of genocide," said the presidency.

The "memorial" -- the name of the document detailing South Africa's case against Israel before the ICJ -- cannot be made public but laid out evidence in "over 750 pages of text, supported by exhibits and annexes of over 4,000 pages", it added.

South Africa in December brought a case before the ICJ, arguing the war in Gaza breached the 1948 United Nations Genocide Convention, an accusation Israel has strongly denied.

Several nations have added their weight to South Africa's proceedings against Israel, including Spain, Bolivia, Colombia, Mexico, Turkey, Chile and Libya.

While ICJ rulings are legally binding, the court has no concrete means to enforce them.