Opposition leader questioned over threat to Mugabe

Zimbabwe's opposition leader has been summoned to Harare's police headquarters for questioning over remarks he allegedly made calling for the overthrow of Robert Mugabe.

Morgan Tsvangirai, leader of the Movement for Democratic Change, was asked, through lawyers, to verify he had advocated Mugabe's removal in a speech to a party rally in May, said police spokesman Wayne Bvudzijena.

The comments could constitute an offence of "undermining the office of the president" under a recently passed security law, which carries a maximum 20 year sentence.

Tsvangirai was questioned for two hours before being freed without charge, but was warned he may be prosecuted at a later date, said opposition spokesman Nomore Sibanda.

"They called him to the police station and read him the allegation that he uttered a statement which is criminal, threatening or demeaning President Mugabe," he said.

Tsvangirai has already been charged with treason for plotting Mugabe's overthrow and is out on bail pending trial. If convicted he could face the death sentence.

Mugabe's increasingly authoritarian government has cracked down on the opposition, the independent press and the judiciary.

The government repeatedly has ignored court orders, instructing police not to enforce them, and last year expanded the Supreme Court bench in an apparent bid to pack it with sympathetic judges.