undetected

Last year, the Electoral Commission was publicly reprimanded for a litany of security failures that allowed hacking groups to spy undetected, after breaking into databases and email systems.

She added: "Xu is a serious danger to women, and without the bravery of victims who came forward, his offending may well have continued undetected."

Prosecutors alleged that Wright had been disconnecting his helicopters' flying-hour meters so that their long flight times - which exceeded official standards - could go undetected, and he was worried that he would be found out.

Hundreds, if not thousands, of cases have probably gone undetected, he said.

That the activists were able to enter and exit the air base undetected prompted the government to order a review of the security of all UK military bases.