When she arrived at the Harare Magistrate's Court with a plastic bag of personal effects in one hand, she joked with friends and her captors.
The celebrated human rights lawyer, arrested on March 17 for allegedly blocking police from searching the home of a client, was showing the kind of defiance that has made her a frequent target of Zimbabwe's security forces.
An urgent high court application for her release was granted by Justice Charles Hungwe at 2am on Monday, and was served on the police 30 minutes later. Officers refused to comply.
The official line is that she is being charged for "defeating and obstructing" the course of justice.
Mtetwa, who was born in Swaziland but moved to Zimbabwe in 1983, has built her career on defending human rights campaigners, journalists and non-governmental organisations.
In a 2008 interview with Marie Claire magazine, she traced her rebellious streak to her childhood; her father was polygamous, and she felt there was "injustice in the way things were done" in her family. She told the magazine: "I was always questioning my father's authority — and always getting into trouble."
Mtetwa was busiest after the 2000 parliamentary election, when she led a challenge against results in close to 40 constituencies.
Mtetwa is a friend of journalists, having defended dozens of local and foreign reporters. The story is often told of how she saved Andrew Meldrum, a correspondent for the Guardian and the Economist, from deportation in 2003, arriving at the airport just minutes before take-off to serve immigration staff with a court order stopping the deportation.
In 2007, Mtetwa was grabbed during a protest march against the intimidation of lawyers. She was beaten and dumped by a roadside. When she lifted her skirts to allow a photographer to record the bruises she suffered, she attracted ridicule from her opponents. Early this month, Herald columnist Nathaniel Manheru — widely believed to be President Robert Mugabe's spokesperson George Charamba — in an article arguing that anti-Mugabe activists use misfortune to draw attention to themselves, mocked Mtetwa for "baring her inner portions to display Zanu-PF's well-marketed brutality".
Despite her international clout, she has remained grounded. Reacting to the news that the Committee to Protect Journalists had awarded her its international press freedom award, she said: "I didn't do anything other than my job."
Mtetwa has won the adoration of many of her colleagues. "She has stood by many of us; it's time we stand by her," said Zhuwarara, part of the legal team that fought to free her this week.
Mtetwa is a board member of the Zimbabwe Lawyers for Human Rights. The group said: "For every Beatrice Mtetwa that these state agents and institutions put behind bars and attempt to embarrass, humiliate and punish without lawful cause, there are 10 other human rights lawyers waiting to take up the mantle."