A man who shoved a balloon of marijuana up his nose in prison finally had the calcified clump of illicit drugs removed 18 years later.

The 48-year-old man wedged the packet of marijuana up his right nostril after his girlfriend slipped him the contraband during a prison visit almost two decades ago.

A file photo showing marijuana seized by police. The case in "BMJ Case Reports" was the first reported “prison-acquired marijuana-based rhinolith” in the world, the clinicians wrote. Credit:AP

The strange case has been chronicled by a group of Sydney doctors in BMJ Case Reports under the title "A nose out of joint".

The man evaded his prison guards but when he tried to retrieve the drugs he accidentally pushed the balloon deeper into his nasal cavity, according to the report.