Scotland has been labelled a "soft touch" for polluters because the fines for environmental crimes imposed by Scottish courts are 36% lower than in England and Wales.

A new report by the Scottish Environment Protection Agency (Sepa) reveals that the average fine for pollution offences in 2011-12 was £5926, compared with £9336 south of the Border.

Environmentalists say this makes it easier for criminals to get away with wrecking the environment in Scotland. Sepa accepts there is a problem, but insists it is being tackled.

Sepa's report for 2011-12 says it referred 37 cases to procurators fiscal, served 124 statutory enforcement notices and 160 final warning letters. Most action was taken against waste companies for illegal dumping, fly-tipping or transfers.

The Highland Park distillery was fined £15,000 for discharging diesel oil into an Orkney stream and the Caledonian Cheese Company in Stranraer was fined £20,000 for failing to upgrade its effluent plant.

Of those convicted by sheriff courts for environment offences, four were in Edinburgh, three in Perth, two in Glasgow, two in Hamilton and two in Dunfermline.

Dr Richard Dixon, director of Friends Of The Earth Scotland, said: "The potential fines are pretty much the same between the two systems so you can only conclude the Scottish legal system is not yet taking environmental crimes seriously enough. Scotland is a soft touch if you want to get away with trashing the environment for the sake of a quick profit."

Sepa's director of operations, Calum MacDonald, who is leading an environmental crime task force, denied the organisation was a "soft touch". However, he admitted: "There is an ongoing issue here that we are trying to tackle."

Sepa is working with the Crown Office, procurators fiscal, the police and courts, he said, "but sentencing is a matter for the judiciary and the Scottish and English legal systems are different".