In early April, Hajizada and Milli were transferred from a holding center in Baku to two prisons further afield. The mens' lawyers complained that the move would separate the two men and subject them to intense isolation and potential violence.
Adnan's father, Hikmet, told RFE/RL's Azerbaijani Service that Emin Huseynov, director of the Institute for Reporters' Freedom and Safety and a close friend of the blogger, was among those blocked from visiting.
The move appears to contravene Azerbaijan's obligations under the European Convention on Human Rights, which protects the rights of prisoners to receive their choice of visitors. A Justice Ministry spokesman, however, says individual prison heads have the final say in such matters.
"Only visitors who can positively affect an inmate's rehabilitation are allowed to visit," said Mehman Sadiqov of the ministry's press office. "But the point is that this prisoner is a new inmate, and the head of the prison needs some time to decide whether Hajizada's friends may see him."
Hajizada has just over a year remaining in his sentence.
For the 30-year-old Milli, who is serving the remainder of his 2.5-year-sentence in Saylan 5, 120 kilometers from the capital, the problem appears to be access to reading material.
"Since his detention in July 2009, he's read 120 books," Rashad Shirin, a friend of Milli's, told RFE/RL. The books include works by Vaclav Havel, Martin Luther King, and "New York Times" columnist Thomas Friedman. But reading material is in short supply at Saylan.
Shirin says a special group has been set up on Facebook -- Books for Adnan and Emin -- to help supply the bloggers with more books from the United States and Europe.
-- Ulviyee Asadzade