A Polish national involved in a two-vehicle crash near Draperstown was more than six times the legal drink drive limit, Magherafelt Magistrates Court was told.
Piotr Primar (37), of Glenelly Villas, Draperstown, faces charges of driving while having consumed excess alcohol and having no insurance.
Ordering a pre-sentence report, Deputy District Judge Peter King warned the defendant that his liberty was at severe risk.
A prosecuting lawyer told the court that police were tasked to the accident at Glenelly Villas on August 31 last year.
She said one of the vehicles was on its side and the occupant could not get out.
Counsel said police officers detected a strong smell of intoxicating liquor from the defendant who provided a preliminary breath test which showed an alcohol count of 214mgs.
She said Primar was later taken to Antrim A&E where a blood specimen was obtained revealing an alcohol reading of 301mls.
Defence solicitor Patrick McGuckin explained that defendant had been drinking at home most of the day and had foolishly decided to drive to a shop.
Describing the breathaliser reading as “absolutely astounding”, Mr King said it was the highest he had come across in his 20 years of practice and possibly one of the highest readings ever recorded in Northern Ireland.
He suspended Primar from driving and adjourned the case for a month.