Cape Town - President Jacob Zuma says he is not the person to ask about the reasons for Zimbabwean first lady Grace Mugabe being granted diplomatic immunity by one of his own ministers. Democratic Alliance leader Mmusi Maimane pressed Zuma during a round of follow up questions in Parliament, asking him what the reasons were for allowing Mugabe to leave the country following allegations of assault. "I'm not a lawyer. I don't know the points of law, and I was not involved in this process. How it was done, I would be lying if I speculate," he told the National Assembly. "So I'm not going to give you an answer that is not there." Democratic Alliance MPs could be heard sarcastically crying, "That's our president!", which was followed by Zuma's customary laugh.'I can't answer'Agang SA MP Andries Plouamma followed up by asking how Zuma could "open the country up to abuse", and allow foreign leaders to come into the country and beat citizens. "I have not opened the country up to abuse," Zuma said. "Part of the reason we have laws in the country is that when someone commits a crime, there are law enforcement agencies who deal with that. "The police were very active and very involved in dealing with that matter."He then said, "I don't know what happened, and how the matter came to the point that it came. "The actions were taken, the police were there, they dealt with the matter, then the issue of diplomatic immunity came about, and I can't answer that detail. I can't lie." Mugabe returned back to Zimbabwe a week after allegedly assaulting South African model Gabriella Engels.Minister of International Relations and Cooperation Maite Nkoana-Mashabane had granted her diplomatic immunity in what she called a "painful" decision. The original question was asked by Inkatha Freedom Party MP Liezl van der Merwe, who wanted to know what message the Mugabe debacle sends to the country. 'I don't know'She also asked if Zuma would investigate ministers in his Cabinet after Minister of Social Development Bathabile Dlamini claimed "there were worse" people in government than former deputy higher education minister Mduduzi Manana. Manana is currently out on bail after video footage of him assaulting a woman at Cubana in Johannesburg emerged. "Standing here, I don't know who the people are who are abusing women. I'm sure those who have knowledge will do the right thing. "In my Cabinet, I don't know, I haven't seen anyone. I'm sure if I knew, I'd be able to report." A determined Van der Merwe pressed Zuma further, saying he had not answered the question in full, and wanted to know if he would follow up with Dlamini and do something about the allegations. "It's no good to tell us that he is passionate or committed to [fighting] gender-based violence, but he is not willing to take action himself." Zuma said he can ask Dlamini what she meant, but that he could not "be running up and down" after every utterance from a member of government. The portfolio committee on international relations and co-operation meanwhile resolved last week to invite Nkoana-Mashabane to explain her decision in Parliament at the soonest possible date. The DA has applied for direct access to the Constitutional Court to have the diplomatic immunity granted to Grace Mugabe set aside.