The university demanded the fourth year student handed over or destroyed all copies of documentation about an expected cash surplus running into millions of pounds from university-run housing, after Pi Media ran a story on its existence.
It has been accidentally been made available via a shared Microsoft Outlook calendar.
A letter also warned she could face “various sanctions” including “dismissal without notice and potential exposure to court proceedings” if she published any further information from the documents.
Rebecca said she signed the letter out of fear for her university career.
Jem Collins, SPA Chair, said: “We cannot condemn this kind of kind of behaviour strongly enough. No student journalist should be threatened for doing their jobs.
“With the background of the rent strikes at UCL, it is also blindingly obvious that this story is demonstrably in the public interest.
“Universities and unions need to realise that student journalism there to hold them to them account – not be a PR tool – and that threats like this are completely unacceptable.
“The SPA will continue to work with both Becky and the team at Pi Media to make sure this does not get swept under the carpet. ”
An earlier statement from the NUJ General Secretary Michelle Stanistreet condemned the university’s response.
“The NUJ supports student journalists and student journalism. It appears that the university has behaved in a disgraceful fashion by intimidating [Pinnington] in this way.
“The information is clearly in the public interest and she appears to have acted in a proportionate and responsible way. We expect the university to retract its threats.”