Debris in rivers would be one of the targets of a crackdown

Activists argued the ordinary court system was failing to prosecute enough pollution and wildlife crime cases.

They have said that special courts, with more expertise were needed.

The Scottish Executive said it was examining the demand and an official have-your-say exercise would begin in the spring.

Members of FoE highlighted at a conference in the capital that only 100 of the 8,000 water pollution alerts in Scotland over the last four years had led to a prosecution.

'Derisory' fines

They added that only a handful of wildlife crime cases came before the courts each year.

Campaigners also said that fines, less than �5,000 in most cases, were "derisory".

Green courts have already been set up in Sweden and New Zealand and the proposal in Scotland is that they would handle criminal and civil cases.

Deputy Environment Minister Rhona Brankin said that ministers were committed to at least considering environmental courts.

Ecologists have called for tougher measures in the pipeline

Prosecutors last year outlined plans to target crimes such as polluting rivers with raw sewage or chemical spillage and dumping rubbish.

The scheme was launched by the Crown Office and Procurator Fiscal Service (COPFS) and the Scottish Environment Protection Agency (Sepa).

Leaders of the Scottish Green Party welcomed the crackdown, but it said it was long overdue.

They added at the time they would like to see the executive "move on its parliamentary agreement to develop environmental courts".