testimony of an informant represented the only evidence against petitioner

Barajas v. Wise, No. 06-15494 (9th Cir. March 23, 2007)
Clearly established federal law requires the prosecution to provide reasons specific to the case in litigation if it declines to disclose the names and addresses of key witnesses. Grant of habeas relief in a drug-related case is affirmed where the testimony of an informant represented the only evidence against petitioner, and the state provided no reasons specific to the case for why it should not disclose the requested information.
http://caselaw.lp.findlaw.com/data2/circs/9th/0615494p.pdf