On Monday, BBC1 screened the first of 10 programmes about the work of the National Missing Persons Helpline. Each programme lasts 45 minutes and will be screened daily at 9.15am over the next two weeks, which is the charity's busiest time of the year.
"It's a time for family gatherings so it can be very painful for the relatives of the missing person," explained Ross Miller, press and publicity manager. "They know there will be an empty space at the table."
The BBC ran a similar series earlier in the year and last autumn, but this is the first time it will be running programmes over two consecutive weeks. Leopard Films produced all three series after approaching NMPH for advice on how best to make a film about missing people. The production team was given unprecedented access to the charity and also followed the Metropolitan Police's missing persons unit in Hackney.
Miller said: "The majority of missing people return within 72 hours, but our series focuses on the long-term missing. In these cases, the police have exhausted all their lines of enquiry and the families turn to us for support - we are the only ones who will keep publicising their cases.
"One of the programmes will be screened on the day before the 14th anniversary of a particular missing person. The timing is completely deliberate on our part, and we will publicise the programme in the local press.
"We once managed to reunite a family with a relative who had been missing for 16 years, so it is possible."
The second series, in May, was watched by 43 per cent of viewers, the highest rating ever scored by the BBC in that time slot. That series was also shown in the morning.
"We had a huge increase in the number of calls we received as a result of the programme," said the spokesman. "We had people reporting sightings as well as new people registering missing loved ones."
The charity will also benefit from a mobile phone 'amnesty' during the fortnight. The amnesty will be launched by London's LBC 97.3 FM next Monday, and NMPH will receive £5 for every mobile phone donated.
The campaign has managed to garner support from the Mayor of London, Ken Livingstone, environmental website Recycle for London and the Metro newspaper. All the mobile phones received will be donated to developing countries or fully recycled.