Students at DePaul University in Chicago have created a covert system for distributing contraceptives in defiance of a ban imposed by the Catholic university.

The scheme, called “the womb service,” emerged after the university revoked recognition of its Planned Parenthood Generation Action chapter earlier this year.

DePaul, the largest Catholic university in the United States by enrolment, prohibits the distribution of any form of birth control on campus. Administrators said the decision to shut down the group was linked to its ties with Planned Parenthood, the nation’s leading abortion provider, and stressed that the university reserves the right to restrict health-related supplies it considers contrary to its mission and values.