Prior to the 2011 elections that ushered Sata into power, the then-opposition leader promised to free the media from government interference.
But immediately after taking office, he sacked journalists who had been critical of him as well as the heads of state television and newspapers.
In June the government blocked local access to the Zambian Watchdog, a hard-hitting online newspaper.
This month police detained three journalists with ostensible links to the publication, which does not publish its reporters’ names.
Clayson Hamasaka and Thomas Zyambo were held in Lusaka without charge for more than 24 hours after police night-time raids.
Zyambo was eventually arrested and charged with “being in possession of seditious material with intent to publish”.
Police had found him with hand-written biographical notes on Sata.
Five days after Zyambo’s release, police arrested and charged investigative journalist Wilson Pondamali with unlawful possession of a restricted military pamphlet.
They later added “theft of a library book” to the charge sheet.
A judge granted the reporter bail last Friday but police refused to release him.
Two days later Pondamali was hospitalised after collapsing in prison.
Local access to Zambian Watchdog has now been blocked again, as well as a mirror website set up by Paris-based media rights group Reporters Without Borders.
Another online publication, Zambia Reports, has also been blocked. It reported this week that authorities are also studying barring the news sites’ Facebook and Twitter accounts.
“Journalists are being arrested and charged with theft of novels, when we all know that they are just being harassed for doing their job – informing the public,” exiled journalist Lloyd Himaambo told AFP via email.