The documentary features the work of officers protecting Scotland's wildlife

Wildlife Detectives follows Tayside-based Alan Stewart and three colleagues over the course of a year from spring through to winter.

They protect the country's animals, plants and birds from criminals who want to exploit wildlife for financial gain or in the name of sport.

Mr Stewart, from Perthshire, took up his full-time position in 1997.

Since then he has helped mould current wildlife legislation. He works with Tayside Police in a civilian capacity, after years as a police officer on the force.

When I started doing this, wildlife crime law was pretty poor Alan Stewart

He will appear with colleagues Mark Rafferty, based in Jedburgh, who started his police career with the Met in London, keen birder Ruaraidh Hamilton, based in Haddington, East Lothian, Finlay Christine, based on Mull, and Mark Maylin in Glenrothes, Fife.

In the first episode in the BBC2 series, Mr Stewart deals with cases of thoughtlessness, rather than malicious criminality.

One is an instance of a domestic dog being let loose to kill a roe deer in a wood.

Elsewhere, a call from a member of the public, in Balerno on the outskirts of Edinburgh, concerns suspected illegal badger-baiting ring.

Meanwhile on Mull, Mr Christine looks at a success story of conservation but one which entails constant monitoring.

The detectives' caseload also includes illegal possession of birds of prey, mysterious sightings of big cats, dolphin harassment, indiscriminate poisoning of wildlife, illegal hare coursing, shooting of protected species, bird trapping and even some moss theft.

'Continuing developments'

Mr Stewart said: "About a third of our work is investigation, a third is prevention and a third is the education and training of other police officers.

"When I started doing this, wildlife crime law was pretty poor.

"The powers for the police were pretty poor. The courts couldn't imprison anybody for wildlife crimes. All that has changed.

"Now the law is extremely good in Scotland. And it is developing and improving the whole time. Hopefully I'll be in the job for a long time yet to see these developments continuing."

It took a year to film the documentary to allow any criminal cases which had been brought to go through the court system.