The number of single-use carrier bags being handed out by retailers has dropped by more than 80% since the 5p charge was introduced six months ago.

Four retailers have donated more than £1 million to good causes as a result of the bag charge, brought in in October.

Indicative figures based on reports from businesses show the measure has dramatically reduced the number of carrier bags being handed out.

Over the coming months, Zero Waste Scotland will collect data on carrier bag use and funds raised for good causes ahead of the first official figures being released later this year.

Asda is indicating a more than 90% reduction in single-use carrier bag use, while raising £350,000 for two social enterprise charities.

The Co-operative Food has used the 5p charge to raise £375,000 for community projects across Scotland, reporting a usage reduction of 80%.

Marks & Spencer has raised £214,374 for good causes, reporting an overall usage reduction of around 50% in the past six months, while Morrisons has also reported an 80% reduction, and funds raised for the Morrisons Foundation.

Environment Secretary Richard Lochhead said: "I'm delighted that in just six months the carrier bag charge is already making such a big impact in Scotland.

"I very much welcome the dramatic reductions in carrier bag use being reported by these major retailers. It suggests that many consumers are now in the habit of reusing bags, which should reduce the amount of litter that blights our communities and natural environment, and costs a fortune to clean up."

Lang Banks, director of WWF Scotland, said: "Before the charge, Scotland consumed a staggering 800 million carrier bags every year, many of which ended up polluting our environment and threatening wildlife. So, it's really great to see just how successful this initiative has been."