South Sudanese President Salva Kiir has abruptly dismissed his Environment Minister, Abdallah Deng Nhial.
Kiir announced the dismissal on state television on Wednesday evening but gave no reason for the firing.
Some speculated that the firing might be linked to an altercation Deng had with another member of parliament last week, Machok Majong Jong of the disputed Abyei region.
"He insulted me and I slapped him," Deng said.
"The parliament established a high-level committee to investigate us... I stood before the committee and he did the same -- that one who was slapped and who insulted me,” he said.
Deng said he told the committee he is willing to apologize, but only if Majong does the same. The argument was over whether Abyei should join South Sudan or remain part of Sudan, he said.
Members of the Ngok Dinka ethnic group voted recently in an unofficial referendum to become part of South Sudan, although neither country's government has recognized the poll.
The parliamentary committee investigating the fight has not yet released its findings.
Majong did not respond to several phone calls and text messages from VOA for comment.
Deng took over the environmental post in August after President Kiir reshuffled his entire cabinet. The sacked minister was a candidate for the presidency of Sudan in 2010.
Now that he has been fired, Deng said he plans to return to the University of Juba, where he taught Arabic before he was appointed to Kiir's cabinet.
The firing leaves two vacancies in Kiir's government -- Deng's position and the Minister for the Office of the President, which was not filled earlier this year when Kiir sacked his entire cabinet.