Shin Eun-mi, 53, has been temporarily banned from leaving South Korea following claims that she planned to return to the U.S., having already ignored an initial police summons.

Shin, author of a book on North Korea, is accused by local civic groups of repeatedly showing sympathy towards the North’s regime in recent weeks while she toured the country with former South Korean opposition party spokesperson Hwang Sun.

According to 19 groups representing North Korean defectors, the pair defamed them when they claimed that up to 90 percent of refugees from the North want to return home.

The Seoul Metropolitan Police Agency is investigating whether any of their remarks broke the National Security Law of South Korea -- where even praising North Korea is considered an “anti-state” activity.

A new summons asks that Shin present herself for questioning this Sunday at 5 p.m. (8 a.m. GMT), police said according to local news agency Yonhap.

Officers have also searched Hwang’s home and office.

Shin wrote of her experiences travelling with her husband in North Korea between 2011 and 2012 – something South Korean citizens are banned from doing without permission.

“South and North Korea have to recognize our national tragedy and demand our reconciliation. No one should be able to understand the separation of our brothers and sisters,” stated her article for online publication OhmyNews.

While Shin reportedly insists her remarks were not pro-Pyongyang, her most recent forum came to a sudden stop Wednesday in the southern province of North Jeolla when a high school student was said to have thrown an incendiary device on to the stage.