The court heard McMillan supplied heroin from a phone box

George McMillan, 40, was convicted of supplying the drug in Ayr and Stranraer between 1 and 23 September last year.

The court hear how the accused had begun the operation while on licence for a previous drug dealing conviction.

Sentencing McMillan, Lord Carloway said he had "made a career of violence and drug dealing".

Defence agent Maurice Smyth described his client's crime as a "bizarre and blatant drug operation devoid of concealment or strategy."

He said news had spread quickly that there was an obvious line of supply from McMillan's home and a nearby telephone box and that police had not needed to carry out much of an investigation.

'Ridiculous situation'

Mr Smyth added: "It was a ridiculous situation and jeopardised a promising future."

The court heard that the offences had been committed at a time when McMillan, who lived with his mother in Ayr, had secured financial backing to start up his own building business.

The accused, who also has a previous conviction for violence after suffering a head injury, said he had been trying to turn his life around.

In sentencing him to eight years detention, Lord Carloway said: "I am paying particular attention to the steps you have taken to rehabilitate yourself following your last sentence.

"However, you have a record that shows you made a career of violence and drug dealing."