A college employee responsible for British citizenship tests has been suspended after an allegation of "improper conduct".
Applicants must pass the test before gaining UK citizenship
The Evening Standard claimed an Albanian gang had arranged help with completing the tests.
Barnet College in Colindale, north London, said the test centre at Grahame Park had been temporarily closed.
A Home Office spokesman said the college had suspended a staff member pending a disciplinary investigation.
"There is an allegation of improper conduct during the administration of a Life in the UK test."
The Home Office added the police would be called in if any criminal activity was suspected.
Barnet College principal Marilyn Hawkins: "Following allegations concerning the validation of citizenship tests, a member of staff at the local Grahame Park estate One Stop Shop Centre was suspended immediately.
"Following further allegations, the One Stop Shop Centre, which is used for our community learning programmes outside of the main college, has been closed temporarily to allow a thorough investigation to take place.
"The College has contacted the police about the allegations and is being advised by them as to the best way forward.
"There was nothing to indicate that the work of the supervisor involved was causing concern.
"The College is determined to root out the truth behind these allegations that have involved one of our outreach centres."
A reporter from the newspaper posed as a Moldovan man and is said to have handed over £700 in a cafe before being taken to the college centre for the computer-based question and answer test.
He was told to use a code word when he arrived and his test was completed by a member of staff, the paper reported.
The Life in the UK test has been administered by University for Industry (UFI) since October last year and can be taken at 99 Learn Direct centres across the country.
The 45-minute test, which includes questions about British traditions and the way the country is run, was brought in by the Home Office to gauge how willing applicants were to become UK citizens.
A test pass certificate must be included with a citizenship application form.
A spokeswoman for the Metropolitan Police said the force has not yet received a complaint about the incident.