Democratic Alliance (DA) leader Mmusi Maimane was deported to South Africa, for reasons unknown, when he landed in Zambia, his spokesperson Graham Charters said on Thursday night.
Charters said when Maimane arrived at the Lusaka Airport at around 6:30 on Thursday evening, there were members of the police and immigration police already waiting for him on the tarmac on the runway.
"They stormed the plane. Then things got a bit physical when they tried to remove Mr Maimane from the plane. When Mr Maimane tried to reach for his phone, his phone was confiscated by the legal authorities."
Charters said there was a stalemate between Maimane and authorities for about half an hour, while Maimane demanded to know why he was not allowed into the country.
"He was then ordered to take the next flight back to South Africa."
Charters said the authorities did not give any reason for the ill-treatment "and the blocking of a constitutional office bearer, of a fellow African state".
"At a time where Africa needs to be moving towards a maturing democracy, and upholding the values of the rule of law, we can see that many of our African brothers and sisters are still subject to the regime of big-man politics," Charters said as the incident happened and the country celebrated Africa Day.
"He was not harmed but he was certainly shaken. There was a scuffle to get his phone but he was not physically harmed."
Charters said Maimane had been deported back to South Africa and has landed.
"We call on the South African government to take immediate action against such apartheid-like actions by the Zambian government," he said.