Vanished: The Hunt for Britain's Missing People

Every 90 seconds someone is reported missing in the UK. Most are found within hours, many are located in a matter of days but there are some who seem to disappear, often with little or no trace. Dan Walker investigates people who have gone missing - some cases well known, others not, and each with a unique set of circumstances. Dan speaks directly to loved ones, families, friends, police and experts from charities.