Metal theft in the UK has become such a big problem that police in London have created a unit dedicated to tackling the crime.

As well as taking thousands of dollars worth of telecoms cable and copper wire, thieves are becoming more audacious - targeting public statues and war memorials in what has become a lucrative business.

The thefts include a piece of work by the celebrated sculptor Barbara Hepworth, that had been standing in a park in south London since 1970 and was insured for $800,000, which was stolen earlier this month.

Al Jazeera's Laurence Lee reports from London.