Their representatives have identified at least 11 properties which are owned by the government of Zimbabwe, including houses in Cape Town worth hundreds of thousands of pounds. Unlike properties in Pretoria which are connected to the embassy, the Cape Town properties are thought not to be protected by diplomatic immunity.
The lawyers say it will be a groundbreaking development, as they are not aware of any precedent for government-owned properties being seized in pursuit of a civil judgement.
The timing is awkward for Mr Zuma. This week the South African president called for Western sanctions to be lifted against Mr Mugabe and his cronies, during a state visit to Britain. The EU recently renewed sanctions for another year, although Western officials point out the sanctions hit only only specific regime members rather than the Zimbabwean people as a whole.