U.S. State Department spokeswoman Heather Nauert said Washington was deeply concerned about the detention of Gui Minhai, 53, who is a Hong Kong-based publisher specialised in often thinly sourced tabloid-style books about China's leadership.
"We are deeply concerned that Swedish citizen Gui Minhai was detained on January 20. We call on Chinese authorities to explain the reasons and legal basis for Gui's arrest and detention, disclose his whereabouts, and allow him freedom of movement and the freedom to leave China", Nauert said.
"The United States and our European partners are bound by shared principles of liberty, equality, and human dignity. We will continue to coordinate with our partners, allies and regional organizations on promoting greater respect for human rights in China", she added.
The Swedish government has reportedly said that Gui was taken into custody last week while he was travelling with two Swedish diplomats to seek medical treatment.
Gui has published books on the personal lives of President Xi Jinping and other Communist Party leaders. (ANI)