Despite asking the general public for help on the programme, there has been a deathly silence from the police, and nothing reported in the media.

Not true. After the programme was aired, Scotland Yard received and were sifting through thousands of calls/emails, some which they seemed to be taking very seriously and have spent the last week travelling through Europe (Germany and Ireland were at least 2 destinations I heard) speaking with people whose information seemed credible enough to warrant travelling.

I dont remember whether I read this in a news article or heard it on the radio, but I definitely heard it on Wednesday, in any case, the statement made is definitely untrue.