Statisticians have revealed that illegal drugs and prostitution will boost the value of the UK economy by around £10 billion.
Both activities are worth 0.7% of GDP, equal to agriculture, accommodation services, such as hotels, or publishing industries, including newspapers and magazines.
European Union (EU) rules mean the Office for National Statistics (ONS) will for the first time have to include illegal activities in its official estimate of the total value of UK goods and services, also known as gross domestic product (GDP).
Based on 2009 prices, the ONS has estimated prostitution will add £5.3 billion to GDP, while drugs will boost the economy by £4.4 billion. In all the years between 1997 and 2009 the impact ranges from £7 billion to £11 billion, statisticians said.