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.

The Scottish Environment Protection Agency (Sepa) has issued dozens of warnings, most of them in Tayside.
People in the Borders and Dumfries and Galloway have been asked to pay close attention to the weather forecast over Christmas Day into Boxing Day.
Warnings were also in place on Christmas Eve covering Strathglass and Callander.
Storm Eva is expected to bring further bad weather to areas which have already been badly affected.
A weather warning of heavy rain is in place for much of southern Scotland from 15:00 on Christmas Day through to 23:45 on Boxing Day.
Many roads across Dumfries and Galloway were affected by surface water or flooding on Christmas Eve and drivers were asked "slow down and take care".
The A76 Dumfries to Kilmarnock road near to Drumlanrig Castle was reported as "flooded but passable".
The B724 Annan to Dumfries "low road" was flooded with a road closure in place west of Cummertrees.
In Dumfries itself, the Whitesands car parks were closed due to flooding in the area.
High winds also affected the north of Scotland on Christmas Eve with gusty of 60mph to 70mph forecast and up to 80mph over the Western Isles.
Eleven out of 26 Caledonian MacBrayne routes were disrupted but the situation was improving.
Passengers were asked to check on the website, on Twitter @calmac_updates and also on the freephone number 0800 066 5400 for regular updates.
All courses on offer at a college exposed selling fraudulent security qualifications for cash have now been cancelled, the BBC has learned.
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Many parts of Scotland are at risk of flooding over Christmas after more heavy rain affected the country.