The Irish American woman at the helm of the Playboy mansion has passed away after four decades of working alongside kingpin Hugh Hefner.

Mary O’Connor worked as Hefner’s devoted personal secretary for more than 40 years. According to the New York Daily News, she had recently been in bad health before she passed away on Sunday.

The humorous Irish American, who was in her eighties, was often featured in the on E! show Girls Next Door, which is set in the Playboy mansion.

Read More: The Irish woman at the top of Hugh Hefner's Playboy empire

"Mary passed away today." Hefner announced to his 1,300,000 Twitter followers. "We loved her more than words can say."

Former "Girls Next Door" star Kendra Wilson also tweeted about the bad news.

"RIP Mary O'Connor," she wrote. "She was an amazing person who helped me through so much. But I know she's happy with her boo Captain Bob. :)"

Another former playmate Bridget Marquardt tweeted: "Thank you for all the sweet messages," she wrote. "Mary O'Connor will be missed.#RIPMary."

O’Connor’s grandmother, Sarah Brigham Taner, emigrated with her siblings from Co. Tyrone in the mid-1800s for a better life in the U.S.

During a 2010 Irish Voice interview O’Connor recalled her memorable moments working in the Playboy Mansion.

“I had great fun furnishing this house,” O’Connor said.

“It was so much fun going into a store when money wasn’t an issue.”

Watch a clip featuring Mary O’Connor on ‘Girls Next Door’ below