Police raid confirmed suspicions about centre with inordinately high pass rate

The University for Industry, which ran the Life in the UK test programme on behalf of the Home Office, had already begun working with South Yorkshire Police after receiving a tip-off about an inordinately high pass rate at the Sheffield centre.

But what really nailed the directors of City Wide was what officers discovered when they entered the company's premises: none of the seven applicants logged on to take the computer-based test were anywhere to be found.

What followed was an exhaustive and challenging investigation by fraud squad detectives who were faced with potentially hundreds of false citizenship tests, "taken" by applicants from all over the country, many of whom couldn't speak much English at all.

The UK Border Agency were called in to help trace 2,000 people from outside Sheffield who were officially recorded as taking the test in the city.

In addition, piles of paperwork found during the raid left a potentially impossible set of logistics which prompted detectives to focus on a batch of around 200 applicants' forms for forensic tests. Fingerprints and handwriting on City Wide application forms and certificates, along with tracing applicants, formed the heart of the inquiry.

They were helped by the contents of a text message found on the mobile phone owned by one of the City Wide directors, Abdi Rashid Yusuf, which was recovered when his Sheffield home was raided.

The message, sent to the centre's administrator Mubarak Yusuf, said: "Can u do Qasim's, the 2 somalis and da 3 afghans in the top tray."

Detectives were able to trace the identities of three test applicants from the text, all of whom gave statements that they paid hundreds of pounds to obtain a false pass certificate without ever taking the test.

One of them – Abdullah Zadary, an Afghan who had settled in Birmingham – identified Mohammed Jafari, a fellow Afghan who lived near Birmingham, as the middle man he paid 400 to acquire his certificate from City Wide. Jafari pleaded guilty before his co-conspirators went on trial.

Fingerprint evidence on application forms helped implicate another middle man, Dagenham-based Shpetim Ymeri, an Albanian, who also pleaded guilty before the trial.

Police were also following a particularly unusual spike in the demographics of who was applying to take the test in Sheffield with over 400 candidates from the Turkish community in London.

This led them to Mehmet Ince, a Turkish interpreter who worked out of an office in Tottenham. A series of applicants told detectives – and later Sheffield Crown Court – they had paid Ince hundreds of pounds to obtain pass certificates.

Ince's fingerprints were found on large numbers of City Wide application forms, along with his handwriting. Another Turkish man, Halil Dari, who knew Ince, was implicated when his fingerprints and handwriting were also found on a significant number of applications.

At the trial, Ince claimed he had simply received payment for helping applicants fill in City Wide application forms and helping with citizenship applications to the Home Office. Dari decided not to go in the witness box.

Liban Mohammed Yousif was the only City Wide director to decide to give evidence at the trial. He was at the centre when police raided and continued to insist that applicants logged on to take the test had been there but had simply slipped away.

His defence for the false certificates was that impersonators had taken tests on behalf of applicants.