Hong Kong(CNN) A Hong Kong man who sold controversial books about China's elite has returned home after a mysterious three-month absence, according to the city's government.
Lee Bo told Hong Kong immigration officials Thursday that he had been in mainland China to help in an investigation into his associate Gui Minhai and hadn't been kidnapped. Although Hong Kong immigration authorities show no record of him leaving, he didn't explain how he crossed the border.
His case, which came after the disappearance of four of his colleagues, sparked outrage in Hong Kong and internationally over fears he was taken against his will from Hong Kong by Chinese security forces in December -- a city where they have no legal authority.
Beijing has repeatedly said its officials wouldn't do anything illegal.
All five men were involved with publisher Mighty Current and its shop Causeway Bay Books, which sold gossipy titles about Chinese leaders. Two of the group -- Lui Por and Cheung Chi Ping -- returned to Hong Kong in early March.
Lee disappeared from Hong Kong at the end of December, sparking mass protests amid claims that he had been detained and spirited across the border by Chinese police.
Lee told Hong Kong police that with the help of his friends, he had "with the assistance of his friends, returned to China by his own means voluntarily and it was not an abduction." He stated that he was free and safe while in China.
A British passport holder, the UK had said that Lee was "involuntary removed" from Hong Kong and the case was a "serious breach" of a bilateral treaty with China.