An eight-strong team from Scotland Yard's anti-terrorist branch is examining files containing the names of more than 200 suspects understood to be in hiding or living under false names. They include at least 75 Auschwitz guards and former members of the 14th Waffen-SS Galician division, which has been blamed for atrocities.
Officers from the Metro-politan Police are expected to meet Home Office ministers next month to discuss their inquiry, launched after evidence was uncovered by an amateur historian. Police were handed a list of names, most from the Ukrainian-manned unit.
Six thousand of them were allowed to settle as contract labour in Britain at the end of the war and many emigrated, mostly to North America.
Historians say it is unlikely any of these men, now in their 80s, will be prosecuted because of a lack of evidence.
Only one man, Anthony Sawoniuk, has been prosecuted here for Nazi war crimes. He was sentenced to life in 1999 and died in prison last year, aged 84.