A British woman is being held in Egypt because of her links to a non-profit group accused of causing unrest, according to reports on Friday.
The Associated Press said woman, who has not been named, was told to leave a plane bound for London from the capital, Cairo.
According to the news agency, she was not arrested.
At least 10 people have been banned from travelling in Egypt as part of the country's investigation into NGOs.
The crackdown on the NGOs has caused a serious rift between Egypt and the west, with legislators in the US warning that it may cut the billions in US aid to the state should it continue.
The British Foreign Office said it was "aware of the arrest and subsequent release of a British national at Cairo international airport on 10 February" and that it was providing consular assistance.
At the beginning of this month three protesters were killed after riots broke out in both the coastal city of Suez and Cairo in response to violent clashes at a football match in Port Said.
Hundreds of people were injured in Cairo in renewed violence between security forces and protesters angered by the deaths of 74 fans at the football match between Port Said's Al Masry and Cairo's Al Ahly club.
The violence has quickly been channeled into a political contest, with many criticising the security forces for doing less to contain Wednesday's violence. "This was not a sports accident, this was a military massacre!" protesters in Cairo have been shouting, according to Sky News.
It follows a year of unrest in the North African state, which saw president Mubarak removed from power in one of the early changes of the Arab Spring.