The tentacle-like growth of clandestine advertising in American TV shows in the form of product placement has taken another controversial step with the introduction of McDonald's products into regional news programmes.

Several TV outlets have begun to sell the fast-food giant the right to place cups of its iced coffee on to the desks of news anchors as they present morning current affairs shows.

Typical is Fox 5 News in Las Vegas, an affiliate of Rupert Murdoch's Fox television network. Two cups of coffee, their cubes of ice glinting in the studio lights, now daily stand before the channel's morning presenters. The presenters conspicuously do not drink from the cups, which is just as well - the cups contain a bogus fluid and fake ice to prevent the cubes melting.

The New York Times has reported that similar deals to place McDonald's products in news shows are up and running in TV stations in Chicago, Seattle and New York.

Product placement has become a huge branch of advertising in the US, creeping into all areas of entertainment television. Not only are products seen on camera, they also make their way into drama scripts, such as an episode of the popular soap, The OC, which had one character talk about having "a9.com'd" a friend on the day the internet search company A9 launched a Yellow Pages service of the same name.

Advertising and broadcasting content have become increasingly blurred, with new reality TV show, What I Like About You, pitting young women against each other to compete for an acting slot on an advert for Herbal Essences. The ad is then broadcast in a break during the show.

This is the first time product placement has percolated through to news broadcasts. Journalism ethics groups have protested it is another erosion of standards.

"There has been in broadcast journalism certainly, and arguably in all journalism, a drifting away from the standards of straight news in the direction of entertainment," said Roy Peter Clark of the school for journalists, the Poynter Institute.

Fox 5 News has declined to reveal how much it is being paid by McDonald's for the six-month promotion. The station's news director, Adam Bradshaw, said that the product placement was only allowed in programmes that were appropriate, including later morning shows with an accent on lifestyle.

"I would not put it on a straight newscast like my 5 or 10pm news," Bradshaw said.

The other potential difficulty with the new trend in TV news was conflict of interest. Bradshaw said the McDonald's deal would in no way impede the station broadcasting negative news concerning the food chain.

"News is news. Sales is sales. If there's a story about McDonald's we would report on it just like anyone else," he said.

He added that in such cases he would remove the coffee cups from the newscasters' desks, in a similar way to the pulling of adverts for airline companies during newscasts that report an air crash.

TV stations across America are suffering from a downturn in advertising, partly due to the challenge of the internet and partly due to the country's more recent economic troubles.

In a harsh financial climate, many are turning to new cash streams, such as Fox 5 News's latest innovation.