Reinfeldt met journalists in Boao on the southern Chinese island of Hainan on Saturday afternoon in connection with the ongoing Boao Forum for Asia and after a meeting with China's president Hu Jintao.
"We had a longer discussion about human rights. One could say that we continued our discussion from Stockholm last year," he said.
"I appealed to the president to grant the human rights activist Hu Jia the chance to be re-united with his family. Furthermore we handed over a list of 13 people and requested that they be released."
Reinfeldt's bold approach was welcomed by Amnesty International Sweden secretary-general Lise Bergh.
"It is important that we are kept informed as to what is happening in China. Taking up specific cases is a way of doing so. It probably helps these people who are being held in custody," Bergh said to news agency TT.
Opposition leader Mona Sahlin welcomed Reinfeldt's actions but complained that it was regrettable that the prime minister had not divulged what he had planned to say to his Chinese hosts before departing Sweden.
"I am sure that those of you that have been around a while understand that our meeting could easily have been cancelled at the last minute. That kind of thing happens in this part of the world," Reinfeldt responded in defence of his decision not to reveal his intentions in advance.
Reinfeldt held a half hour meeting with Hu Jintao in connection with the Boao Forum, known as "Asia's Davos." The theme for this year's conference was the climate and the environment and these were the subjects that dominated discussions between the two leaders. In addition Reinfeldt raised the issue of Tibet with Hu as well as China's widespread use of the death penalty.
Hu Jia is one of China's most well-known human rights activists. He was sentenced on April 3rd to three and a half years imprisonment. When Hu Jia was taken into custody in December he had already been held under house arrest for 200 days with his wife Zeng Jinyan - also a well-known human rights activist, and his young daughter.
The EU has previously requested the release of 34-year-old Hu Jia. His sentence raised the attention of the outside world and the EU and the USA were quick to register protests. UN human rights commissioner Ann Arbour and Amnesty International also condemned the sentence.
According to the defence Hu Jia was convicted and sentenced for having distributed information on the internet and for having talked to foreign journalists.