Huseynov was shot seven times
Elmar Huseynov, 37, started his journalistic career in the early 1990s when he joined the independent Russian-language Zerkalo newspaper.
In 1995, he set up the weekly Monitor magazine.
Monitor has been consistently critical of the Azerbaijani government, former President Heydar Aliyev, and the current President Ilham Aliyev.
Recent articles have highlighted human rights, torture in Azerbaijani prisons following a recent prison riot, and the plight of the army.
The Justice Ministry once forced Huseynov to publish a disclaimer, apologising for allegedly misleading statements in one of his articles.
Threatened with closure, Huseynov published the disclaimer, but then in an editorial note he refuted it in its entirety and protested against the violation of his constitutional rights.
The government has also tried to close down the printing companies where Monitor is produced, but following protests from the public and the diplomatic community, the authorities acknowledged that the closure was illegal.
Monitor was critical of President Ilham Aliyev and the government
Over the past several years, government officials have confiscated copies of Monitor from state and private newsstands across Baku and charged Huseynov with defaming the Azerbaijani population, insulting the honour and dignity of government officials, and spreading libellous information.
Nevertheless, in recent times the magazine has become more easily available, with vendors selling it on the streets in Baku.
But all Baku-based printing companies are currently refusing to produce the magazine.
In one of his last interviews with the BBC, Huseynov said his work had ceased to be that of a journalist and had turned into guerrilla warfare.
"When I am hit below the belt, it is difficult to think of ethics. I have developed my own code and this code is not the code of a journalist," he said.
"This is a code of guerrilla war. We are not a media outlet. We are guerrillas."
Huseynov, who graduated as a construction engineer, also established the Bakinskiy Bulvar newspaper which was known for critical reporting and hard-hitting commentary.
The newspaper had a small print-run and published for two years before it was closed down by the government.
BBC Monitoring selects and translates news from radio, television, press, news agencies and the Internet from 150 countries in more than 70 languages. It is based in Caversham, UK, and has several bureaus abroad.