John McKenzie

April 10, 2010— -- John McKenzie is an ABC News correspondent based in New York where he specializes in medical reporting for "World News with Diane Sawyer."

McKenzie has covered many of the controversies in medicine, from stem cell research to screening for breast and prostate cancer. His cutting edge reports have highlighted the promise of experimental cancer treatments, the advances in hospital care, to the hidden risks of popular medications and misleading health claims of many food companies.

From 1993 to 1995, McKenzie was a correspondent for the ABC News magazine "Day One," where his reports included in-depth profiles of boxer Evander Holyfield and singer Tony Bennett, and where he earned Emmy nominations for his reports on Down syndrome and young tennis ace Venus Williams. He also won a Western Heritage Award for his investigative report on poaching in Yellowstone National Park.

Prior to joining "Day One," McKenzie was a New York-based general assignment correspondent for the network. McKenzie covered all forms of domestic and international stories. He was among the first journalists deployed to cover the U.S. invasion of Panama and the Iraqi invasion of Kuwait.

In addition to appearing regularly on "World News Tonight with Peter Jennings," McKenzie provided reports for "Nightline" and was a substitute anchor for "World News This Morning" and the news segments of "Good Morning America."

McKenzie joined ABC News in 1980 to open the network's bureau in Warsaw, Poland, where he covered the start of the Solidarity Movement there. With the Soviet Union threatening to invade Poland, McKenzie filed daily reports to all ABC News programs. He later became a roving foreign correspondent, spending months at a time in Beirut, Moscow, Tokyo and London.

McKenzie covered such stories as the Soviet invasion of Afghanistan, the Iran hostage crisis and the Israeli invasion of Lebanon. He has worked throughout Europe, the Middle East and Far East, as well as from several African and South American countries.