A world-first CCTV system which can detect when rubbish is being dropped is being developed in Scotland in a bid to tackle the scourge of litter louts across the nation.

Zero Waste Scotland has issued a tender notice calling on researchers and firms to develop and test software which can monitor "littering behaviour".

The Scottish Government funded-agency wants to create a new method to allow it to evaluate whether schemes which attempt to discourage people from dropping litter are actually working.

It says the aim is to develop an automatic image recognition system which can capture the 'motion' of rubbish being discarded, allowing CCTV to record the number of instances of littering over a particular time period.

Zero Waste Scotland said the system, if successfully developed, would be a world-first and could be used by other countries to help implement ideas to prevent littering.

However privacy campaigners have raised concerns about such technology being used to catch people littering in the future, saying it appears to be a "disproportionate and potentially expensive" solution to the problem.

According to the latest figures, at least 15,000 tonnes of litter is dumped every year and Scotland spends at least £53 million of public money on tackling the problem - including £45 million spent by local authorities solely on cleaning it up.

David Barnes, programme area manager for litter and fly-tipping at Zero Waste Scotland, said: "There are a lot of countries in the world which are very good at cleaning up litter and the cleanliness standards in Scotland have continued to go up. But I think there is a recognition that we just can't continue to spend that money (on tackling litter).

"It is much more cost-effective to prevent litter, and if we can get this working this would be a very powerful tool in terms of helping to identify what works and what doesn't work. There would then be a lot of interest in that from other countries."

Barnes said an example of a litter prevention project was painting footprints on a street leading up to bins to encourage people to use them. But he said the only way at the moment to assess if such as scheme was working was to have people physically watching how many bits of rubbish were still dropped.

He added: "That is not really cost-effective on any sort of scale, so what we are hoping to do is develop a system which would actually allow us to then start monitoring these types of interventions in a much more robust way, which would be a first in the world. We are trying to put Scotland at the forefront of litter prevention."

Barnes said experts considered the idea technically feasible, but the next stage would be to assess how long it would take to develop the CCTV system and assess whether it is financially viable. He also insisted the aim was not to catch individuals who were dumping rubbish.

"The way the system will be set up will be to record instances of littering, so it won't be taking photographs of people's faces," he said.

"It is the type of movement - such as a small object breaking away from a larger object - that would be that type of thing the software would be looking out for, rather than scanning people's faces."

However Daniel Nesbitt, research director of privacy campaign group Big Brother Watch, said: "Zero Waste Scotland's plan to use CCTV - something that is intrusive and often ineffective - to monitor the success of anti-littering schemes seems a disproportionate and potentially expensive solution to a problem.

"If the larger intention is to use this technology to catch and potentially prosecute people who litter they must be open and honest about their plan."

He added: "Before putting this scheme in place Zero Waste Scotland must ensure they have properly considered its implications. They must understand exactly how invasive each camera may be and whether or not there is actually a better way of going about this."