An Oklahoma inmate claiming to have suffered with an erection for 91 hours is suing his prison for failing to offer medical care.

He also claims he was mocked, rather than offered medical assistance when he tried to raise the issue with his jailers.

According to Tulsa World and the Washington Post, a 32-year-old former prison inmate, Dustin Lance, suffered a permanent injury as a result of his erection.

In December 2016 Lance swallowed a mystery pill given to him by another inmate, and then reportedly endured an erection for 91 hours.

He alleges that it took four days since swallowing the pill before he was given proper attention.

The lawsuit is a $5 million civil rights case, because of treatment - or lack of it - given to him at the Pittsburg County Jail.

In a bizarre twist, county officials filed a petition to dismiss Lance's case on the grounds that he was dead - something which his lawyer reportedly put down to a 'scirvener's error', in an email sent to Tulsa World.

Priapism is the medical term for an erection that will not go away.