Katherine Heigl has used the Emmy Awards to fuel a spat with Grey's Anatomy producers. [Agencies]

Actress Katherine Heigl, a surprise Emmy winner last year for her role on hit TV drama Grey's Anatomy, has bowed out of this year's race in an apparent swipe at producers for diminishing her presence on the series.

Heigl, 29, quietly chose not to submit her name for consideration as an Emmy contender this year but explained her rather conspicuous absence from the ballot when asked by Tom O'Neil, columnist for the Los Angeles Times' showbiz awards website TheEnvelope.com.

"I did not feel that I was given the material this season to warrant an Emmy nomination, and in an effort to maintain the integrity of the academy organisation, I withdrew my name from contention," she said in a statement posted by O'Neil.

"In addition, I did not want to potentially take away an opportunity from an actress who was given such materials."

The lengthy list of performers vying for Emmy recognition from fellow members of the Academy of Television Arts and Sciences was posted in recent days. Nominations will be announced on July 17.

Heigl was the upset winner of last year's prime-time Emmy as best supporting actress in a drama for her role as Dr Izzie Stevens on the ABC hospital series, beating out two other co-stars for the award - Sandra Oh and Chandra Wilson.

It was the show's biggest Emmy triumph since the 2005 inception of the series, which helped lead the way in ABC's ratings rebound three years ago and ranks as one of the most watched dramas on US television.

But while Heigl has since emerged as Hollywood's latest "it" girl following the success of her breakout film comedy Knocked Up, her profile on Grey's Anatomy this past season has been noticeably reduced.

As noted by O'Neil, one of her more meaty story lines on the show this year involved her character saving a deer that had caused a string of automobile accidents.

"What she deserved after winning the Emmy was a heightened profile on the show, not a reduced one," he said, adding that she appeared to be "logging an internal protest" with the show's producers.

While not uncommon for Emmy veterans to withdraw from contention in later years - as Candice Bergen and Bill Cosby have in the past - they typically have done so after repeated wins to give others a shot.

A spokeswoman for ABC, a unit of the Walt Disney Co, said the network has no comment on Heigl's move.

Heigl's last big-screen role was in the romantic comedy 27 Dresses, which released in January.

Daily Variety reported this week that she has just clinched a deal to star in and produce a film adaptation of Escape, the best-selling memoir of Carolyn Jessop, whose testimony helped convict polygamist sect leader Warren Jeffs.