Robert Oliphant Maxtone-Graham was fined yesterday after admitting he had hundreds of pounds worth of the illicit drug at his Perthshire home.
The 57-year-old was caught after calling police to his rural cottage to investigate an ongoing dispute with another man.
He told police he had been given a large lump of cannabis from a former friend and complained to the officers about the poor quality of the drug.
His own solicitor said it was "a somewhat unusual case" and would never have come to light had his client not called police.
Perth Sheriff Court was told Maxtone-Graham tried to hand the cannabis at the local police station but was told to go away because they were too busy.
The aristocrat then asked officers to come to his home.
Maxtone-Graham admitted possessing cannabis worth almost £600 at his home between September 6 and October 2 last year and was fined £360.
Fiscal depute Rebecca Kynaston said: "While the police were making inquiries it became clear there were controlled drugs within the property."
Solicitor Jamie Morris, defending, said: "The expression that comes to mind when you look at the circumstances is that it was an own goal.
"A friend offered some cannabis to Mr Maxtone-Graham. He accepts he is an occasional smoker and, when presented with a gift horse, agreed to accept it.
"The substance arrived and it became clear it was of extremely poor quality. He then fell out with the friend. As a strategy of getting back at his friend he contacted police."
The father-of-two, known as Rob Maxtone-Graham, 18th of Culoquhey, can trace his lineage back to the 1200s when the family was gifted the land of Cultoquhey near Crieff.
The original Maxtone later died in the battle of Flodden in 1513. Among his ancestors are the 1st Earl of Atholl, the 1st of Balgowan, Bishop of Moray, Andrew Rollo 6th of Duncrub and 1st Earl of Montrose.
Educated at Glenalmond College, Maxtone-Graham was a member of the cross-party groups on Tourism, Renewable Energy and Scottish Traditional Arts.