One for the US Embassy I would think.
See here:
http://www.usembassy.org.uk/cons_new/visa/niv/vwp3.html
Quote:
Important: Some travelers may not be eligible to enter the United States visa free under the VWP. These include people who have been arrested, even if the arrest did not result in a criminal conviction, those with criminal records, (the Rehabilitation of Offenders Act does not apply to U.S. visa law), certain serious communicable illnesses, those who have been refused admission into, or have been deported from, the United States, or have previously overstayed on the VWP. Such travelers must apply for special restricted visas. If they attempt to travel without a visa, they may be refused entry into the United States.
