Police arrested a senior minister Friday after he called President Robert Mugabe a liar, the party of Zimbabwe's prime minister said.
Hard-liners in Mugabe's party accused Jameson Timba of insulting Mugabe, an offense under sweeping security laws, when he said Mugabe lied over the outcome of a recent regional summit on Zimbabwe's political and economic crisis.
The former opposition party of Prime Minister Morgan Tsvangirai said in a statement police accused Timba of "undermining the authority of the president."
Earlier, police spokesman Wayne Bvudzijena said he had no information on possible charges.
Timba, minister of state in Tsvangirai's office, was being held late Friday at the main Harare police station, said party official Nelson Chamisa.
Timba attended the summit and contradicted Mugabe's account that regional leaders withdrew a damning report on the slow pace of reforms and continuing political violence blamed on Mugabe's party.
Mugabe insisted the Southern African Development Community, a regional economic and political bloc, cleared his party's name over allegations reported to the grouping by the chief Zimbabwe mediator, President Jacob Zuma of South Africa.
Timba gave his account of the summit at the same time as Tsvangirai, who told a rally in central Zimbabwe that Mugabe and his party leaders lied over the summit findings.
Tsvangirai was expected to return to Harare on Friday from a meeting of international jurists in Spain.
Mugabe's party has also called for his arrest for insulting Mugabe, accusations usually applied to remarks made by political hecklers or those who curse Mugabe in bars or on buses. Those convicted have been fined or briefly jailed.
Tsvangirai's party described as "strange" that Timba was arrested before the weekend _ a reference to a common police practice of jailing suspects over the weekend in filthy, overcrowded cells in frigid winter conditions until courts and judicial offices reopen on Monday.
His arrest signaled another rift in the 28-month coalition formed by regional mediators after violent, disputed elections in 2008.
Tsvangirai's party said late Friday it "demands that the minister is treated with the respect he deserves" in accordance with the laws of the country.