While Pakistan and Britain point fingers at each other over why 10 of the 12 suspects arrested in terror raids last week held student visas, one former immigration official is alleging Britain's student visa process is a farce.

"We caseworkers observed that very many, if not most, of the English language schools the supposed students said they were to attend were obvious fraudulent set-ups," Steve Moxon wrote in the Sunday Times of the visas he came across while working in Britain's Home Office's Managed Migration division."

Moxon wrote that the abuse runs rampant because it is, "very easy to do and get away with."

"You can hide among the sheer volume of students, and sign up to a course - real or fake - for a very low fee," he said.

Twelve people, including 10 Pakistani nationals, were arrested Wednesday after raids across Britain.

And, while he stopped short of alleging officials condone such practices, he points out some problems with enforcement.

"Ex-caseworking colleagues of mine who remain in situ tell me that still they are not allowed to refuse to grant more than a tiny percentage of applications, irrespective of how meritless they may be," Moxon wrote. "Staff are also still told by senior caseworkers that they must not refuse an application if there is any risk of the would-be migrant appealing the decision. Most of the legally required evidence to support an application is still not checked."

Click here to read more of what Moxon wrote in the Sunday Times.

Click here to read more on the raids.

Click here to read more on the immigration system battle between Pakistan and Britain.