STOCKHOLM (Reuters) - Swedish publisher Gui Minhai, who has been held by Chinese authorities off and on since 2015, was examined by a Swedish doctor in a Chinese hospital on Monday, Sweden’s foreign minister said.

The Chinese-born Gui, 53, who is a Swedish citizen based in Hong Kong and who has published books critical of China’s leaders, was abducted in Thailand in 2015 and brought to custody in mainland China.

In October last year, he was released, only to be seized again in January by Chinese agents in the presence of Swedish diplomats.

Swedish Foreign Minister Margot Wallstrom said in a statement that Swedish medical staff had seen Gui on Monday, a visit originally planned for March.

“This is welcome. Out intense work continues and will be followed up in different ways,” she said.

“Sweden’s position is known and remains - Gui Minhai must be set free and able to reunite with his family.”

Sweden complained in March that Chinese authorities had denied a promised visit to Gui by a Swedish doctor, calling the move “unacceptable.” China responded, saying the publisher himself had rejected the visit.