Estimates of undocumented immigrants in Canada range between 35,000 and 120,000. James Bissett, a former head of the Canadian Immigration Service, has suggested that the lack of any credible refugee screening process, combined with a high likelihood of ignoring any deportation orders, has resulted in tens of thousands of outstanding warrants for the arrest of rejected refugee claimants, with little attempt at enforcement. A 2008 report by the Auditor General Sheila Fraser stated that Canada has lost track of as many as 41,000 illegal immigrants.