The women had repeatedly applied to protest in one of the designated parks
Two elderly Chinese women could face a year in a labour camp after repeated attempts to hold a public protest, a close relative has said.
Wu Dianyuan, 79, and Wang Xiuying, 77, had applied repeatedly for permission to protest in Beijing's much feted but little used Olympics "protest parks".
They remain at home but could be sent away immediately if they make any more fuss, said Ms Wu's son, Li Xuehui.
Chinese authorities said they had no record of the sentences.
The penalty of "re-education through labour" allows police to imprison a suspect for up to four years of labour without a formal charge or trial.
Ms Wu and Ms Wang were forcibly evicted from their Beijing homes in 2001, to make way for development.
They have been fighting for restitution ever since - and had applied multiple times for permission to protest in one of three areas supposedly set aside for demonstrations by the government.
But on Monday, Beijing's public security bureau revealed that none of 77 applications to protest had been approved - and the vast majority "withdrawn" for further "consultations".
Relatives of some of those who had applied for permission alleged that they were detained instead.
Ms Wu and Ms Wang remain at home, but Mr Li said they were under constant threat of being taken away.
"Wang Xiuying is almost blind and crippled. What sort of re-education through labour can she serve?" Mr Li told the Associated Press.
"But they can also be taken away at any time."
'Spotlight on rights'
China promised to improve its record on human rights seven years ago, when it was awarded the 2008 Games.
It announced the establishment of designated protest zones last month.
International Olympic Committee spokeswoman Giselle Davies reportedly said she would look into the cases of Ms Wu and Ms Wang
She defended the IOC's decision to award the Games to China, saying it had forced the debate about human rights in the country into the spotlight.
But Nicholas Bequelin, from Human Rights Watch, told AP that the women's plight was "part of the tough tactics used to intimidate and silence protesters", and said China's use of arbitrary detention was "beyond the pale".