A climate scientist widely known for the "hockey stick" graph of recent temperatures has won the right to keep his e-mail private amid unsubstantiated allegations he might have rigged research data.

Virginia's top court ruled Thursday that Michael Mann's electronic communications, generated while he was a professor at the University of Virginia, are a shielded, "proprietary" [PDF] work product.

The Energy Environmental Institute, formerly the American Tradition Institute, and a local lawmaker sought the e-mail under the state's Freedom of Information Act. The institute objects to claims that global warming is caused by greenhouse gas emissions.

Mann's troubles began in 2009, when hackers stole e-mail messages from the Climatic Research Unit of the University of East Anglia in Britain.

One e-mail from the center's director noted a "trick" in one of Mann's articles that appeared in the journal Nature. Mann, now at Penn State, has maintained that the e-mail was taken out of context.

Mann has become famous for his attempts to reconstruct the climate of the past 1,000 years. The original "hockey stick" graph suggested that the past few decades have been the warmest period in more than 1,000 years. Subsequent research by Mann and others has replicated his general conclusions.

Media groups urged the Virginia Supreme Court to demand disclosure. The Reporter's Committee for Freedom of the Press said that e-mail "among professors is not entitled to a blanket treatment as proprietary" and "must be subject to public scrutiny."