On the day of the incident in Malmo on June 19, Thunberg wrote in an Instagram post that protesters had blocked the road for oil trucks in the Swedish southern city's harbour.
"The climate crisis is already a matter of life and death for countless people. We chose to not be bystanders, and instead physically stop the fossil fuel infrastructure. We are reclaiming the future," she had said.
If convicted for disobeying a police order, Thunberg can be handed a fine or up to six months in prison.
"You have the freedom to demonstrate, but you must not demonstrate in such a way that it causes disturbances for others," prosecutor Charlotte Ottosen said, according to the daily Sydsvenskan.
The Swedish central prosecutor's press office could not immediately confirm the report when contacted by Reuters for comment.
Thunberg's representatives could not be reached.
