Anna Lindstedt is accused of brokering an unauthorised meeting during her time as ambassador to get publisher Gui Minhai freed, a statement from the prosecutor’s office said.
Gui Minhai, a Chinese-born Swedish citizen known for publishing gossipy titles about Chinese political leaders out of a Hong Kong book shop, disappeared while vacationing in Thailand in 2015 before resurfacing in mainland China.
Lindstedt, who is working as a foreign ministry official without an international posting, could face up to 10 years in jail if convicted.
“An ambassador is the head of a public authority with a far-reaching mandate to represent Sweden,” deputy chief prosecutor Hans Ihrman said.
Nevertheless, even ambassadors had to follow the guidelines set down by the foreign ministry and the government, he added.
“In this specific consular matter, she has exceeded her mandate and has therefore rendered herself criminally liable,” Ihrman said.
She has been charged with arbitrariness during negotiations with a foreign power, a first in modern times, he added.
Relations between Sweden and China have been strained for several years over Gui Minhai’s detention.
Gui Minhai disappeared from a vacation home in Thailand in 2015. Several months later, he appeared on Chinese state television confessing to a fatal drunk driving accident from more than a decade earlier.
He served two years in prison but three months after his October 2017 release, he was again arrested while on a train to Beijing while travelling with Swedish diplomats.
His supporters and family have claimed his detainment is part of political repression campaign orchestrated by Chinese authorities.
According to prosecutors, Lindstedt organised a meeting in January between Gui Minhai’s daughter and businessmen with contacts to the Chinese state.
The Swedish authorities opened their investigation the following month.
Angela Gui, who has been actively campaigning for her father’s release, wrote in February on her blog that Lindstedt had invited her to Stockholm in January.
During discussions in the lounges of a hotel in the Swedish capital, in the presence of Lindstedt, she was introduced to Chinese businessmen who claimed they could help secure her father’s release.
In exchange, Angela Gui said she was told to “stop all media engagement”.
The Chinese embassy in Stockholm has said Beijing “has never authorised and will not authorise anyone to engage with Gui Minhai’s daughter”.
In November, Sweden’s Culture Minister Amanda Lind defied a Chinese threat of “counter-measures” by presenting a Swedish rights prize awarded to Gui Minhai.