Heroin is the drug most commonly mentioned in law offences locally, according to a Europe-wide study, while cannabis is more commonly mentioned throughout most of the rest of Europe.

Heroin accounted for 30 per cent of drug offences in 2010 in Malta, replacing cocaine as the biggest offender, according to the annual report of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA).

In all other countries except the Czech Republic, Latvia and Lithuania, cannabis was the most commonly reported drug seized.

Between 2005 and 2010, the number of drug offences involving cannabis increased in 15 countries, resulting in an estimated increase of 20 per cent in the European Union.

However, Malta reported a downward trend, together with Germany, Italy, Austria and The Netherlands.

Meanwhile, Malta continues to have a problem with heroin purity, which makes users more prone to overdose.

The average purity of brown heroin in Europe tested in 2010 ranged between 17 and 28 per cent, but in Malta it hit 30 per cent. This is six percentage points lower than the purity reported in 2009 when the European average ranged between 16 and 32 per cent.

Higher purity rates in 2010 were only reported in Spain (32 per cent) and Turkey (57 per cent), while the lowest were reported in France and Austria (13 per cent).

Heroin, which is a white powder in its purest form, is frequently cut with other substances for dealers to maximise their profits, restricting the absorption of the drug.

According to the EMCDDA report, Malta is among four countries with the largest problem of opioid use, together with Ireland, Latvia and Luxembourg.

According to the report, synthetic opioids, such as fentanyl and buprenorphine, are replacing heroin, which has become less available in Europe in recent years. The countries with the smallest problem are Cyprus, Hungary, Poland and Finland.