Hugh Hefner alters Crystal Harris 'Playboy' cover

Hugh Hefner has altered the picture of his ex-fiancée Crystal Harris which appears on the cover of the new Playboy issue.

Harris called off her engagement to Hefner this week but still appears on the front of the July instalment alongside a headline reading 'America's Princess: Introducing Mrs. Crystal Hefner'.

Hefner has now added a red sticker saying 'Runaway Bride In This Issue' to the front of the magazine. "Recent events call for a special sticker on the July cover. Look for it on newsstands," he told Twitter followers.

A spokesperson for Playboy told Reuters that the sticker will only appear on newsstand issues because subscriber copies have already been mailed.

Hefner confirmed his split from Harris on Twitter, saying: "The wedding is off. Crystal has had a change of heart." He also joked that he had arranged to watch the Julia Roberts movie Runaway Bride later that night.

Playmate Harris said in a later statement: "After much deep reflection and thought I have decided to end my engagement with Hef. I have the utmost respect for Hef and wish him the best going forward. I hope the media will give each of us the privacy we deserve during this time."

The 25-year-old has since told Ryan Seacrest that marrying Hefner wasn't the "right thing" for her to do.

"For a while I've been having second thoughts about everything," she added. "I haven't really been at peace with myself lately. I didn't think it was really fair to him... They were gonna air a show on it. It was all happening too fast for me."

Hefner and Harris announced their engagement on Christmas Day.

> Holly Madison, Bridget Marquardt send support to Hefner