A rape survivor has described an attack last month on two couples strolling in a Johannesburg park that was so horrific that it shocked even crime-calloused South Africans.

In an online video, the woman told the Times Live news site that a group of men tied up her partner and another man with their own clothes and threw them into a lake. She said they told the bound men to swim. Then one of the assailants raped her.

Both men drowned. A second woman managed to escape the attack.

Local media reported that a 24-year-old man suspected to be part of the group of attackers appeared Monday in court.

Police told reporters the couples were attacked by a gang of 12 men around dusk on a Saturday evening in October.