Nine employees in the US District of Columbia have been given their marching orders for watching pornographic websites on government PCs during work hours.

The sackings follow a five-week investigation into the computer usage habits of municipal employees by the city's Office of the Chief Technology Officer.

The sacked workers were said to have visited an "egregious" number of pornographic sites between 1st January and 31st December 2007, according to an official statement released by Washington Mayor Adrian Fenty's office.

The investigation, which involved the forensic analysis of 10,000 city computers, was undertaken after an employee at the Office of Property Management made a formal complaint about fellow colleagues using their work PCs to download pornographic images.

The investigation is ongoing and could lead to further action against users found to have violated computer use policies, according to the statement.

The sanctions, based on the number of visits employees have made to porn sites, range from a warning letter to suspension and termination.