Secret papers: Blacks seen as threat to national security in the Sixties

Black people are potential spies. They have to be treated as security risks unless they can show evidence of their "assimilation" into Britain and "their trustworthiness in handling its affairs".

That was the judgement, 30 years ago, of the top civil service coordinator of the nation's intelligence services, except he used the word "coloured". According to a report he compiled for the Ministerial Committee on Security in September 1967 - now released under the 30-year rule and open at the Public Record Office - coloured people may become "disaffected through real or imagined acts of racial discrimination; consequently they may be vulnerable to inducements offered by hostile intelligence services or to the influence of subversive organisations".

Sir Laurence Helsby, whose day job was permanent secretary to the Treasury, headed the Official Committee on Security. He was reporting to ministers on the operations of the vetting system and told them few blacks were likely to pass "positive vetting" - the procedure in which a full background check is compiled by the police and Security Service (MI5).

Immigrants had to have lived in the UK for at least 10 years before they could be positively vetted; even then they would not be considered for the diplomatic or security services. "Staff not of UK origin in general cannot be assumed to have an inherent loyalty to this country. The risk to security which arises may, however, be reduced if there is satisfactory evidence of their assimilation into this country and of their trustworthiness in handling its affairs." Sir Laurence was a clever man and conscious that he could sound racist. The problem, he explained, lay in checking the backgrounds of coloured immigrants in their countries of origin. He was aware, too, that there was a growing problem.

Immigration into the United Kingdom had been controlled since the early Sixties but, this being the era of full employment, Whitehall was recruiting large numbers of black people into manual and junior clerical jobs. In London, nearly half the intake to clerks' positions in some departmentscomprised black people. But they could not be trusted with classified documents. And that posed management problems.

It could be, said Sir Laurence, that someone with less than 10 years' residence might provide evidence of their assimilation. Conversely, someone might have lived in Britain for more than a decade and still not "put down firm roots".

l A Home Office spokesman said yesterday that nowadays the Government was an equal opportunities employer which did not discriminate on grounds of colour - and that includes the Security Service, MI5.

Positive vetting rules were applied regardless of colour. However, the Cabinet Office is known to be disturbed by the relative lack of ethnic minority people in senior positions across Whitehall.