Five Japanese people who recently returned from the United States and Mexico have all tested negative for swine flu, officials said on Wednesday.
Japan has yet to confirm any cases of the A(H1N1) strain, although some people have tested positive for the influenza A virus that causes swine flu.
The country has been on top alert for the virus during one of its busiest travel periods of the year, the "Golden Week" of public holidays when tens of millions of people crowd trains and airports to visit family and friends.
Among the latest to test negative for swine flu were three girls and a mother and her baby, all of whom had recently returned from Mexico and the United States, health officials said.
"As the result, we have no suspicious case in Japan right now," a health ministry official said.
Around 30 people who were sitting near the suspected cases on their flights home had also been quarantined but had now been released.
Meanwhile, local media reported that fear of swine flu has discouraged some Tokyo doctors from seeing potential patients.
Since Saturday, Tokyo authorities have received 92 reports of physicians refusing to see feverish patients, the reports said.
Some of the complaints said a patient was refused care because the person worked at Narita Airport, Japan's main international airport, the reports said.