A now-fired Philadelphia police sergeant has spent seven months in solitary confinement after a judge held him for contempt for failing to unlock his computers in a child-porn investigation.

Computer privacy advocates say the government has no right to force Francis Rawls to potentially incriminate himself.

But federal prosecutors armed with a search warrant believe the hard drives contain "very graphic images" of child pornography.

Rawls has appealed the contempt finding to a federal appeals court in Philadelphia.

Staff Attorney Kim Walsh of the Electronic Freedom Foundation says it's only the second appeals court to weigh the issue.

Rawls is being held in solitary confinement for his own protection as a former police officer.

He at one point tried to unlock the computers for police but said he could not recall the passwords.