Amnesty International said today that Britain has refused entry to asylum-seekers who risk being returned to countries where they could face imprisonment, torture and death. A report by the London-based human rights group said Britain's refugee-determination system fails to uphold its obligations under the U.N. Convention on Refugees. ``As many as 100, and possibly many more, persons seeking asylum in the United Kingdom have been summarily and unlawfully expelled without a proper examination of their asylum claim,'' the 42-page report said without giving a specific number or time frame. ``In addition, an untold number of would-be asylum seekers have been prevented from gaining access to the United Kingdom's refugee-determination process,'' it added. The Home Office, in charge of immigration, said the report failed to recognize that most asylum-seekers were not fleeing political persecution under the terms of the 1951 U.N. convention. It said unfounded asylum claims were now widespread as a means of circumventing normal immigration controls and that Britain has been flooded with applications in recent years. The Amnesty report charged that Britain gives insufficient advice to asylum-seekers and that officials subject them to arbitrary and prolonged detention while their cases are being considered. It said most of those who arrive saying they are seeking asylum have no right of appeal when refused it. It said visa requirements and fines on airlines that arrive with foreign passengers who don't have proper travel documents have combined to obstruct bona fide asylum-seekers from gaining effective access to Britain's refugee-determination system. The Home Office statement said refugee-determination systems throughout Europe and North America are overwhelmed by unfounded claims and that backlogs in the two regions have doubled to more than 400,000 cases since 1985. It said that in Britain, applications for asylum have risen fivefold since 1988 and have reached more than 20,000 in the past 12 months. It said backlogged applications in Britain now number 27,000.