JOHANNESBURG, South Africa - To Zimbabwe's government, James McGee is the undiplomatic diplomat.

McGee, the U.S. ambassador to Zimbabwe for the last six months, has eschewed the tactful, almost invisible role that envoys often take. With foreign journalists largely blocked from covering events in the African nation, McGee and other Western diplomats have adopted a outspoken posture, exposing political violence and ratcheting up the international pressure on the regime.

In turn, McGee has been scolded in the state media, reprimanded by the government, harassed by police and had a staff member threatened with assault. Zimbabwean officials accuse him of breaking the Vienna Convention on diplomats, interfering in its internal affairs and making politically charged and inflammatory comments.

Not that the government's adversaries have been immune from McGee's blunt criticisms. As opposition leader Morgan Tsvangirai stayed in neighboring South Africa while his supporters back home were being beaten and harassed, McGee said he should be in Zimbabwe despite reports of a plot to assassinate him.

McGee, a thrice-decorated Vietnam veteran, traveled with diplomats from Britain, the Netherlands, Japan and Tanzania last week to an alleged torture center in the countryside where government opponents allegedly were interrogated and beaten. The previous week he and others visited the capital's Avenues Clinic, crowded with victims of the regime's violence against opposition activists and supporters.

McGee appears to have gotten under President Robert Mugabe's skin as much as his predecessor, Christopher Dell, who so outraged the regime that the pro-government Herald ran a front-page headline, "Mugabe to Dell: Go to Hell," which the envoy later framed. Dell was put under 24-hour surveillance, according to the Herald.

The day after McGee's fact-finding mission to the interrogation center, during which police blocked his convoy for an hour and threatened to beat a member of his staff, the Herald ran a prominent letter describing the black diplomat as a "political activist for the wrong cause" sent to "do Washington's dirty work in Zimbabwe."

Several days later another Herald article said: "Contrary to his delusions, McGee is not fighting for the democratization of Zimbabwe but is just a big player in the Uncle Tom role long conceived by America."

McGee dismissed the Herald criticisms, saying the paper was "nothing more than an instrument for vituperative and erroneous information."

McGee's missions have played an important part in independently confirming the level of political violence after disputed elections held in March, as well as intensifying diplomatic pressure on a regime that analysts and diplomats see as determined to cling to power. The ruling party lost control of parliament in the election, and Mugabe faces a runoff race with Tsvangirai, expected late next month.

McGee said there was conclusive "damning" evidence that the camp he visited with diplomats was an interrogation center, with small cells where people had been imprisoned. Though the cells were empty during the visit, McGee and his colleagues saw four books with prisoners logged in.

"These notebooks contained some pretty damning evidence," McGee said in a telephone interview. "They had the names of the people. They had the interrogation methods used on these people. It said they were undergoing beatings.

"There were the names of the people they were looking for to interrogate. They were looking for a village head man. He's in hiding now. The book said, 'We want to find him and interrogate him because he didn't stop his people from voting for the MDC,' " he said, referring to the opposition Movement for Democratic Change.

During his visit to the Avenues Clinic, he said, he met a woman in her 80s who had been hit on the head with an ax by ruling party supporters because her grandchildren were associated with the MDC.

"The evidence in the hospital was even more damning," McGee said. "We had some horrific pictures of people who were horrendously beaten for political purposes, people who were beaten to within an inch of their life.

"This type of political violence just has to stop. It is getting out of control, and until it stops I don't think we need to talk about anything else in this country," he said.

McGee said that when he presented his credentials to Mugabe in November, the president invited him to travel around the nation and see things for himself. "He said, 'If you find that things are bad, come back and report them to me.' "

McGee said his attempts to present the evidence from the fact-finding mission to Mugabe were ignored.