Refuse collectors are dumping recycling in the back of bin lorries with waste which is being sent to landfill.

An investigation by the Evening Times found that the contents of blue bins in Glasgow city centre are being mixed with rubbish in black bins.

Signs on blue bins clearly state that they are for paper, cans and plastic bottles, while black bins are for all other waste.

We watched refuse collectors in Buchanan Street dump rubbish from both blue and black bins in the back of a lorry.

When challenged, one worker said they had never been able to separate refuse because blue bins are regularly “contaminated” with general waste.

The refuse collector, who asked not to be named, said: “We can't recycle what's in the blue bins because it's so contaminated - people put all sorts in there.

“The original intention was that we'd be able to recycle things, but from the very start of the scheme we haven't been able to do so.”

The problem could be costing the public purse thousands of pounds because the council is taxed for every tonne of rubbish sent to landfill.

The Scottish Government recently set landfill tax at £84.40 per tonne at standard rate and £2.65 per tonne at the lower rate.

Glasgow sends nearly 165,000 tonnes of household waste to landfill annually, according to official figures.

By 2025, 70% of all waste produced is required to be recycled, with some 95% diverted away from landfill sites like Cathkin.

Environmentalists have called for a new public awareness campaign to discourage people from putting general waste in blue bins.

Friends of the Earth Scotland Director Dr Richard Dixon said: “Glaswegians will be disappointed that their efforts to do their bit and recycle waste are undermined by a minority who just can’t be bothered to do the right thing.

“Glasgow’s citywide recycling rate is very low so the council needs to ensure people understand what to do and are encouraged to use the bins correctly.

“Unfortunately, it is all too common to see coffee cups and leftover food in the wrong bins around the city.

“Glasgow City Council should reveal how much of the city centre recycling is regularly being contaminated.”

Dr Nina Baker, Scottish Green Party group co-convenor and councillor for the city centre, said: “It is a real pity that these recycling bins aren’t properly used but perhaps the council’s cleansing division with Community Safety Glasgow’s litter enforcement teams could do some public education work over the coming months.”

A spokeswoman for Glasgow City Council said: “Everyone can play their part in keeping the city clean, not just the council, by disposing of rubbish correctly and recycling where possible.

“While the near 700 public recycling sites located across the city are used very well, there’s still room for improvement and we urge people to use the on-street bins correctly.”