MI5 chief Jonathan Evans
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MI5 boss Jonathan Evans warns over cyber threat

26 June 2012 Last updated at 18:49 BST

MI5 is working to counter "astonishing" levels of cyber-attacks on UK industry, the organisation's chief has said.

In his first speech in almost two years, Director General Jonathan Evans also said that the Olympic Games were dominating British security concerns.

Gordon Corera reports.