Ran Chen says her father was tortured into making a false confession.
China has executed a scientist accused of spying for Taiwan.
Wo Weihan's family had appealed for clemency, saying that the scientist was tortured into admitting that he was a spy. He was sentenced last year.
The 59-year-old man, who ran his own medical research company in Beijing, was arrested in early 2005.
Among other things, he was convicted of passing Chinese military secrets to Taiwan, which China considers a renegade province.
Court documents said he spied for an organisation called The Grand Alliance for the Reunification of China under the Three Principles of the People between 1989 and 2003.
This group is under the auspices of Taiwan's new ruling party, the Kuomintang, according to China.
His daughter, Ran Chen, who holds an Austrian passport, said her father's death had been confirmed by the Austrian embassy in Beijing.
Mr Wo's family alleged that he had been denied access to a lawyer for a year.
A spokeswoman for the United States' embassy in Beijing condemned the execution.
Susan Stevenson told the AFP news agency that the US was "deeply disturbed and dismayed".
The European Union also voiced its indignation, saying the execution seriously undermined the spirit of trust and mutual respect between the EU and China.
The execution will heighten tensions between China and the EU, says the BBC's Oana Lungescu in Brussels, coming on the same day EU officials raised his case at a meeting on human rights with their Chinese counterparts.
Earlier in the week, Beijing postponed its annual summit with the bloc in protest against plans by EU leaders to meet the Tibetan spiritual leader the Dalai Lama.