Grace Mugabe has increased the type of dairy products her farm produces and is now selling sour milk at the OK Bazaars. The Mugabe milk brands are called Alpha Omega and will soon include powdered milk and ice cream.

Helping to guarantee the success of Grace's products has been the almost total destruction of the dairy industry in Zimbabwe by her husband, Robert. It took just five years after the first land invasion in 2000 to reduce the dairy herd by 80%. Dairy cows were routinely slaughtered for meat or maimed in random acts of cruelty. Viable dairy farms had their milking equipment destroyed and the farmers violently displaced.

Grace's milk products will be a direct challenge to Nestle who produce many of the same milk products and who, under pressure from rights activists, stopped buying milk from Grace Mugabe's farm in 2009.

The First Lady's Gushungo Dairy Estate used to be called Foyle Farm. The previous owner faced a campaign of violence over many months in 2003 and was forced to sell his property to the Agricultural Rural Development Authority. ARDA estimated the price of the property at a quarter of independent estimates and paid the owner just 40% of that amount. As soon as the owner vacated the property Grace Mugabe began to pop in for visits.

Although she has put massive investment into the dairy farm for a number of years it's estimated that the output is less than 35% under the previous owner - who produced more than any other dairy in Zimbabwe.

The UK's Sunday Telegraph newspaper investigated the pay and conditions at Gushungo Dairy and said an average worker would be unable to afford the milk produced. One worker said: "Do we ever get enough money? No, I get $40 (£25) a month, yet we sell lots and lots of milk."

"We do get cabbages returned from the market and 25kg of maize meal twice a month, but there is no electricity in our houses, only for office staff and managers. Mrs Mugabe is here a lot, but doesn't talk to us, just the managers."

Mrs Mugabe told the state Herald newspaper that she had gone into dairy farming because her husband, Robert Mugabe, wanted it. She said: "I did it especially for him."

But it appears that the farm has been useful for other ventures. Rumours abound that Grace had a 5 year affair with Reserve Bank Governor Gideon Gono, and that they met at least 3 times a month at the dairy farm.