The University of Sydney’s Faculty of Arts and Social Sciences has launched an investigation into a controversial assignment requiring students to plant fake stories in the University of New South Wales’ student newspaper Tharunka.

Crikey yesterday revealed students taking the subject Media Politics were instructed to “design and execute a false story that you attempt to get published in the UNSW student newspaper”. The assignment was worth 25% of their final grade.

University of Sydney students, concerned about the ethics of the task, tipped off Tharunka’s editors to the prank. “For someone who’d one day want to go into journalism I have a major ethical problem with trying to print lies,” Media Politics student Joshua Tassell told Crikey.

On Tuesday course co-ordinator Peter Chen defended the assignment to Crikey as a “practical, research-oriented task with a sound paedagogic basis”. By the following morning, however, Chen had told Tharunka the assignment was a “bad idea”. He also admitted he had not received approval for the assignment from the head of his department.

“If I was overseeing an honours student, yes, I would have had to go through all the ethics tests, but as it is, just for teaching, all I have to do is to get my head of department to sign off on it,” he said. “This is where you’re going to kill me, if you ask whether or not I did do that, well, no, I didn’t.”

Overnight, Chen deleted his Twitter account — which featured a number of colourful exchanges yesterday — and a Tumblr blog for the subject where he interacted with students.

A University of Sydney spokesman said he could not comment further on the matter until the investigation was complete.