A wide range of information on Afghanistan's opium production and the nature of the UK heroin problem is available online. The following links helped in the making of this Panorama film.
The BBC is not responsible for the content of external internet sites.
Opium in Afghanistan
UN Office on Drugs and Crime produces an Annual World Drug Report, as well as reports on opium cultivation in Afghanistan.
The International Narcotics Control Board publishes a detailed annual review of global narcotic production, supply and consumption.
The Foreign Office provides information on the UK government's contribution to tackling opium cultivation in Afghanistan.
The Foreign Affairs Committee of the House of Commons conducts hearings and reports on the British government's policy efforts in Afghanistan, including it's counter narcotics policies.
The US Department of State's Bureau for International Narcotics and Law Enforcement Affairs publishes information on the efforts of the US government to counter narcotics activity globally.
Drugs in the UK
Drugs.gov.uk is the government's central website for those interested in its drug strategy.
The Home Office Research Development and Statistics Directorate conducts and publishes a range of research on drug use in British society.
Downing Street's Strategy Unit recently released part of its report on Drugs in the UK under the Freedom of Information Act.
A full version of the report was subsequently leaked to the Guardian newspaper.
The National Criminal Intelligence Service publish an annual threat assessment for the UK, which includes analysis of illegal narcotics activity.
The Independent Drug Monitoring Unit conducts an annual survey of drug prices in the UK.
Drugscope is an independent centre with a range of information and guidance on drugs.