Senior White House Advisers Jared Kushner and Ivanka Trump attend a reception held at the Israeli Ministry of Foreign Affairs in Jerusalem ahead of the moving of the U.S. embassy to Jerusalem, May 13, 2018: REUTERS

A software developer has apologised for deleting reporters’ articles while working under Jared Kushner at the New York Observer.

Austin Smith has claimed he was ordered to delete the stories by the newspaper's publisher, who is now a White House senior adviser.

The developer, who worked at the Observer around 2007 to 2013, claimed in a Hacker News message board post that deleting the stories was the most unethical thing he's done as a programmer.

"After Jared Kushner originally bought the New York Observer, I was hired to lead the tech team, which I did for a year and a half in house then for three more as a vendor," he wrote. "He asked me, out of band, to blackhole articles critical of his commercial real estate colleagues and I complied."

Emails obtained by BuzzFeed News suggest the reason behind Mr Kushner's alleged demands: his attempts appeared to block stories that were critical of his friends, associates and businesses across the city.

In fact, some of the URLs still remain on the Observer website. One appears to be about Neil Rubler, a top executive for the real estate firm Vantage Properties, which had settled a lawsuit from New York’s attorney general over allegedly illegally removing tenants out of apartment properties in order to raise rent. The URL on the Observer does not appear to be favourable towards the executive, indicating he was included in a list of "10 worst landlords."

I found out a few months ago that while I was the editor in chief of the Observer, Jared was instructing our third party tech provider to delete articles critical of his business associates w/out my knowledge. I don't have enough choice expletives describe my feelings about that. https://t.co/EYyEn0YIKI — Elizabeth Spiers (@espiers) August 6, 2018

Mr Smith said he wasn't aware of the ethical issues behind deleting the stories at the time, and has since learned the error of his ways. He previously acknowledged deleting the stories in a blog post on his company website, and reportedly provided his story to New York Magazine for a profile story it published on Mr Kushner. The piece did not include his story, however.

"If I had known about it, Jared and I would have had a big problem," Elizabeth Spiers, the former editor of the Observer, told BuzzFeed News. "Jared... Went directly to Austin because he knew I wouldn't do it."

Other former colleagues of Mr Kushner said he ordered a journalistic hit job against one of his arch rivals in New York real estate; a businessman who he was reportedly told had dirty practices by a source.

Multiple reporters were said to have been assigned to the story, which ultimately led nowhere and became an inside joke throughout the newspaper for months.

One former editor for the Observer wrote a story about his tenure working for Mr Kushner, published in the Columbia Journalism Review. “It didn't take long at the Observer for me to figure out that Kushner didn’t have much respect for the people on his payroll who were reporters,” Kyle Pope wrote in 2017. “When I would approach Kushner about raises for the staff, he would almost always balk, pointing out that if we didn’t boost their pay, there was a line of replacements willing to work for the same salary or less. Journalists, in his mind, were essentially interchangeable, and easily replaceable. The fact that they were so poorly paid was evidence, in his mind, that what they did or how they did it could not possibly be that important."

Under Mr Kushner and multiple other leadership teams, the Observer has dwindled from an iconic paper covering New York’s social and political elite, into a digital-only publication.

The White House and a representative for Mr Kushner did not respond to requests for comment.