Official figures may significantly underestimate the number of suspected war criminals living in the UK, the ex-head of the Border Force has warned.
Brian Moore told BBC Radio 4’s Today programme that tracing people suspected of war crimes who were now in Britain was not the “priority it should be”.
Mr Moore, the force’s former director general, said official numbers relied on those who volunteered information.
Mr Moore told the programme he had concerns about how the UK tracked people who “wield the cudgels, apply the electrodes, or systematically commit rape” during conflicts abroad and then flee to Britain.
Mr Moore, who has set up campaign group Torture Aware UK, said: “War crimes tend to be committed by junior soldiers, prison guards, police officers, security and intelligence agents and these are likely to run into, just over the last 20 years or so, probably hundreds of thousands of people who’ve been involved in war crimes.
“I can’t see a clear strategy that suggests we are trying to answer the question ‘how many people have we got?’.”
Last year, the Home Office revealed how it had identified 115 war crimes suspects making UK immigration claims.
However, Mr Moore said the true figure was likely to be significantly higher and called on the government actively to seek witness statements from victims of war crimes who had also claimed asylum in Britain.
Of the cases confirmed by the Home Office, suspects originated from countries including Afghanistan, Iran, Iraq, Libya, Rwanda, Serbia and Sri Lanka.
Between January 2012 and April 2013, the Home Office researched nearly 800 cases where individuals were suspected of war crimes and crimes against humanity.
It made “adverse recommendations” against 99 people who had applied for British citizenship, asylum or leave to remain in the UK. A further 16 war crimes suspects had applied to enter the UK.
Between 2005 and 2012 more than 700 suspected war criminals were identified by UK immigration officials.