A Los Angeles nun who stole more than $835,000 to pay for a gambling habit has been sentenced to a year in federal prison, according to US media reports.

Eighty-year-old Mary Margaret Kreuper admitted stealing the money from 2008 to 2018 while she was principal at St. James Catholic School in the LA suburb of Torrance. 

The money was spent on gambling trips in Las Vegas luxury holidays at swanky resorts like Lake Tahoe, where rich tourists gather to cruise in the summer and ski in the winter, according to an AFP report.

"I have sinned, I have broken the law, and I have no excuses," Kreuper told the court, according to The Los Angeles Times.

She said her crimes were "a violation of my vows, the commandments, the law, and above all the sacred trust that so many had placed in me."

Kreuper admitted wire fraud and money laundering during a hearing last year.

The court was told how money sent to the school to pay for tuition and charitable donations was instead funnelled into secret accounts that Kreuper controlled.

When an audit threatened to expose the scheme, Kreuper told employees to destroy incriminating documents, the court heard.

The Los Angeles Times reported that when she was initially confronted by the Archdiocese of Los Angeles, Kreuper argued that priests were better paid than nuns and that she thought she deserved a raise.

District Judge Otis D. Wright II told Kreuper that he had wrestled with what to do with her, and acknowledged she had been a good teacher for many decades,

"But somewhere along the line, you just ran completely off the road, and I think you understand that. At least I hope you do," he said.