The testimonies featured in the Panorama programme were taken from a government drug report called Hidden Harm.

This publication was an inquiry carried out by the Advisory Council on the Misuse of Drugs, focussing on children in the UK with a parent, parents or other guardian whose drug use has serious negative consequences for themselves and those around them.

It found that they face physical and psychological harm, often have to fend for themselves, and may have to look after their parents and younger siblings.

The report also estimated that between 250,000 and 350,000 children in the UK have at least one parent with a serious drug problem and that having a parent with serious drug problems causes huge harm to children of all ages.

It said that an effective, joined-up working between agencies was essential; and that the number of affected children was only likely to decrease when the number of problem drug users decreases.