A man who put his fiancée in a cardboard computer box and tried to bury her alive because he was bored with her was sentenced today to 20 years in prison.

Judge Peter Collier at Leeds Crown Court sentenced Marcin Kasprzak, 26, for the attempted murder of his former fiancée Michelina Lewandowska.

"It was your intention that she would not be found. It was your intention that she die there," Collier said during the sentencing. "The death you intended would have been long and slow. It is mind-numbingly awful to imagine the sort of death you intended her to die."

The case gained notoriety when Lewandowska clawed her way out of her intended grave, using the diamond on her engagement ring to dig her way out of the box.

Kasprzak and his friend Patryk Borys attacked Lewandowska with a taser at the couple's home last May, then bound her and stuffed her into a cardboard computer box. They buried her under six inches of dirt and an 88-pound tree branch.

Borys, 18, admitted to kidnapping and was sentenced to four years in prison.

During the trial, Lewandowska told the court she prayed, thought of her 3-year-old son, then gathered the strength to cut her way out of the box using her diamond engagement ring.

Kasprzak admitted to kidnapping, but claimed he only wanted to scare his fiancée. Prosecutors argued Kasprzak had grown bored with the mother of his child and wanted to be rid of her.