Vesna Pesic, a former member of Serbia's Parliament and an opposition leader in 1990s, was summoned by the police to give a statement about her tweet in which the country's officials described it as calling for the murder of President Aleksandar Vucic, N1 reported on Tuesday.
The Higher Prosecutor's Office's immediately started looking into the matter.
"Pesic is not accused, she will be interviewed as a citizen," Irena Balos, the spokesperson for the prosecutor's office told the Tanjug news agency earlier on Tuesday.
After the interrogation, Pesic told N1 she spent some 15 minutes in the police station and answered several questions.
In the tweet she erased after the accusations, Pesic said: "Let's see what you will do when he (Aleksandar Vucic) is declared President for life. All while the Twitter community is tweeting without worries. You are not thinking about this. Putin just did that. If (Ana) Brnabic resigns then you must know - Vucic will be there for life. No boycott (of the next general elections) will help there, only a barrel to the head."
She said she knew that those in power would "twist it around into an attack," adding its last part meant a suicide, not Vucic's murder.
"People know that they twist what is written around for their dumb attacks. I did not even think about something like that," she said.
Vucic said he wouldn't sue Pesic.