AN illegal immigrant drowned in Deep Bay while swimming back to China for the Winter Solstice yesterday. Police said two mainland men were swimming towards Shekou at about 9.30 am when one of them got into trouble. His 42-year-old partner swam back to Hong Kong and alerted police. Rescuers mounted an air and sea search along the waterfront of Tai Sang Wai and Tsim Bei Tsui. Marine Police took the informant on board an inflatable craft to help with the search. At about 1.40 pm, officers found the body of the 30-year-old man. The mainlander's corpse was floating in the estuary of the Shan Pui River, near Deep Bay. The surviving illegal immigrant, who was arrested, allegedly told police he and the dead man had entered Hong Kong in August. They had lived on a hillside and had got by on casual work.