Undercover researchers filmed Ashley Commerce College in Ilford sitting or forging exams for untrained students to become security guards or bodyguards.
Some 20 courses have now been cancelled while authorities investigate. About 90 would-be students have been refunded.
College director Haji Yunis told the BBC he was co-operating with inquiries.
Secretly filmed footage had showed Mr Yunis laughing about the scam he presided over.
He told the researcher that for Â£1,200 he would "bring you in the back door" and "fast track" him to a bodyguard qualification without any training.
Mr Yunis told the researcher not to worry about the police. Fraudulent use of SIA cards in fact carries a maximum six-month prison sentence.
Both the exam board whose certification was fraudulently obtained, Industry Qualifications (IQ), and the Security Industry Authority (SIA) are investigating the college.
An audit is currently taking place, with the aim of ascertaining how many qualifications awarded at the college to enable security guards to become licensed by the SIA were bogus.
Jobseekers must sit mandatory exams to get an SIA card.
A statement placed on Ashley Commerce College's website by IQ read: "Following the BBC broadcast, IQ has been working with the regulators Ofqual and the SIA to formulate a plan for identifying learners affected by the fraud.
"We do expect to find evidence that some learners have received their qualifications without having done their course or tests properly. These qualifications will be reviewed.
"We know that this will leave many learners who attended ACC worried about the authenticity of their qualifications and IQ is working hard to find out how many learners may be affected."
The statement said every student who obtained an SIA licence through the college may be affected.
The college has been operating since 2010.
The statement added: "Where we cannot guarantee that a qualification has not been affected by fraud, we are required to remove the qualification immediately and notify the Security Industry Authority."
Mr Yunis would not say how many students' qualifications were now being reviewed.
Keith Vaz MP, the chairman of the Home Affairs Select Committee, called the fraud a "major scandal".
A Home Office spokesman has said any criminal behaviour would be addressed.
All courses on offer at a college exposed selling fraudulent security qualifications for cash have now been cancelled, the BBC has learned.