Jack Tsang, a reporter from Hong Kong's Now TV News, was heading to Macau by coach over the Hong Kong-Zhuhai-Macau Bridge on Monday, the South China Morning Post reported citing the broadcaster as saying.
The reporter was held for more than two hours and told that he was denied entry "for the next few days".
He was also searched and photographed before he was put on a coach back to Hong Kong, the broadcaster added.
However, a photographer from the same media outlet who was travelling with the reporter was allowed to enter the city.
Both journalists had registered with the Macau authorities in advance, the television network said.
The company said it did not believe the refusal had anything to do with the station's coverage of the anti-government protests in Hong Kong, because its photographer was granted entry.
Security on Hong Kong-Zhuhai-Macau Bridge, the world's longest sea crossing, has been tightened ahead of President Xi Jinping's visit to the former Portuguese colony on Wednesday to celebrate the 20th anniversary of its handover to China.
Also on Monday, officials from mainland China confirmed the detention of a Hong Kong man at the same checkpoint, reports the South China Morning Post.
Chung Sun-ming, 53, was accused of being involved in the smuggling of mobile phones in August 2012. He was reported missing on December 14.
( With inputs from IANS )