Johannesburg - Zambian President Levy Mwanawasa relapsed and was in need of medical intervention after suffering a stroke earlier this year, South African media reported Tuesday, citing a statement of the Zambian Vice-president Rupiah Banda.

"Doctor Mwanawasa had been making steady progress until last night when his condition suddenly changed and required intervention," Banda said late on Monday.

The 59-year-old president had suffered a second stroke while attending an African Union summit in Egypt in June and has been undergoing treatment in a military hospital since.

The president who has been in office since 2002 is regarded as one of Africa's open critics of Zimbabwean President Robert Mugabe. (dpa)