Brighton-based police officer jailed Martin Harris, 37, a former constable based on Brighton & Hove Division, was jailed for two years when he appeared before Hove Crown Court on 16 March.
He had earlier pleaded guilty to misconduct in a public office, possession of indecent images of children and making an indecent image of a child. Temporary Deputy Chief Constable Laurence Taylor said: "We expect the highest possible standards of our officers and staff.
“Protecting vulnerable people is a priority for Sussex Police and we take any report of inappropriate behaviour extremely seriously. “Martin Harris’ behaviour is a violation of the trust that the public put in the police to serve and protect them.
“He has let down victims and his colleagues who carry out an enormous amount of good work with victims of serious offences every day. He has let down Sussex Police and the people of Sussex. “Colleagues reported their concerns about inappropriate messages on Harris’ work phone through our internal reporting system.
Our action to swiftly suspend and then dismiss Mr Harris highlights our determination not to allow a very small number of officers to damage the confidence held in Sussex Police, nor bring into disrepute the honourable service of thousands of hard-working and enormously dedicated police officers and staff across the county.”
Martin Harris was dismissed without notice on January 2 this year when the allegations of breaching standards of professional behaviour relating to discreditable conduct and breaching standards of professional behaviour relating to duties and responsibilities were found.