His multiple roles on the small family run newspaper with a circulation of 3,000 include city editor and part time reporter, but that hasn't stopped Art Cullen from winning a prestigious Pulitzer Prize for his editorial writing.

He scooped the highly coveted journalism award for for his strongly-worded criticisms of Iowa’s powerful agricultural companies in The Storm Lakes Times,

His editorials were “fuelled by tenacious reporting, impressive expertise and engaging writing that successfully challenged powerful corporate agricultural interests in Iowa”, the Pulitzer committee said.

Mr Cullen beat writers on The Washington Post and the Houston Chronicle, both of which have considerably larger circulations and are much more well established.

Founded in 1990, by Mr Cullen's brother John, his wife Dolores and son Tom also work at the newspaper which prints twice a week.

Mr Cullen also works as the city editor, part-time reporter, but he won for his editorials that took on some of Iowa's most powerful agricultural interests including the Koch Brothers, Cargill and Monsanto, and their secret funding of the local government's defence of a big environmental lawsuit.

The investigation into the legal challenge, which had been brought against Buena Vista County for high levels of river pollution from local farms, took several years.

“We felt the public deserved to know who's paying our bills," Mr Cullen told Poynter, a non profit school for journalism. "We did a lot of groundbreaking news reporting and my son, who's 24, did most of the heavy lifting.”

The editor added that he had “lost some friends” in pursuing corporate agriculture, which is one of the largest employers in the area, although Storm Lake is a town of just 14,000 people.

“We’ve always believed that The Storm Lakes Times should be as good at covering Storm Lake as The New York Times is at covering New York,” Mr Cullen told The Guardian.