Belgium's secret service has confiscated guns from its agents following a near miss last year.
Agents can no longer take their guns home after work
Members of the Surete de l'Etat were ordered to disarm after news emerged that an agent only narrowly escaped injury when another opened fire.
Weapons will be issued only if specifically needed, the justice ministry told the BBC News website.
Separately, the work of the state security body may change if a ban on phone tapping is lifted.
Agents could previously take their guns home with them, said Saar Vanderplaetsen, chief spokeswoman for Justice Minister Laurette Onkelinx.
The shooting incident happened in October or November but was only brought to the notice of Surete chief Koen Dassen in February.
A working group is now examining the Surete's internal procedures and Mr Dassen has ordered the confiscation for the period of the study.
Ms Vanderplaetsen said she could not comment on the actual incident, in which the Libre Belgique newspaper reported that an agent who was "without a doubt under the influence of antidepressants" had discharged his weapon.
The justice minister's spokeswoman stressed that Surete agents were not involved in normal police work such as making arrests, but in collecting information.
According to Libre Belgique, however, agents prefer to be armed while out on missions as they often find themselves in hostile environments when investigating, for example, organised crime, and like to think they can defend themselves.
"It's a bit of a shame that they should be taking measures now... when there was never any problem before," one unnamed agent told the paper.
Ms Vanderplaetsen told the BBC that a proposal by the minister to change the law to allow telephone taps could take effect within months.
The measure would give Belgium's secret police similar surveillance rights to those enjoyed by European counterparts.
A report in the UK's Daily Telegraph newspaper notes that the Belgian security apparatus has been a source of frustration for other Western agencies.