An Australian newspaper columnist has apologised after being accused of trying to out the actor Rebel Wilson.

Andrew Hornery, who writes a gossip column for the Sydney Morning Herald, said he regretted how he handled the story, which has been characterised as an attempt to expose the sexuality of the Pitch Perfect star.

Hornery emailed Wilson’s management team last Thursday, saying he knew that the actor was in a new relationship with the fashion designer Ramona Agruma, and giving her two days to provide a comment. Rather than reply to the newspaper, Wilson took control of the announcement and posted about her new girlfriend on her personal Instagram account.

The Sydney Morning Herald’s role in the story would have been unknown if Hornery hadn’t decided to write a column complaining about how he had been scooped by Wilson. He initially complained he had emailed the actor’s representatives to give a heads-up with “an abundance of caution and respect”.

He wrote: “Big mistake. Wilson opted to gazump the story, posting about her new ‘Disney Princess’ on Instagram early Friday morning, the same platform she had previously used to brag about her handsome ex-boyfriend, wealthy American beer baron Jacob Busch.”

The Sydney Morning Herald, which is owned by Australian media conglomerate Nine, has now retracted Hornery’s column after a global outcry, and replaced it with an apology.

Hornery, who identifies as gay, said he made a mistake in how he approached the story, having told management that he had enough sources to confirm the relationship without Wilson’s cooperation. In particular, he said he regrets setting a deadline for Wilson to comment – and insists no decision had been made by the Herald’s editors on whether to run any story.

He wrote: “My email was never intended to be a threat but to make it clear I was sufficiently confident with my information and to open a conversation. It is not the Herald’s business to ‘out’ people and that is not what we set out to do. But I understand why my email has been seen as a threat. The framing of it was a mistake.”

The newspaper’s editor, Bevan Shields, initially backed his reporter and insisted the paper did not out Wilson but “simply asked questions and as standard practice included a deadline for a response”.

By Monday this position had become untenable and – amid an outcry from staff and the story’s timing during LGBT Pride month – the outlet apologised for its reporting.

Hornery said the outlet would in future “make sure we always take into consideration the extra layer of complexities people face when it comes to their sexuality” while reporting on same-sex relationships.

“Celebrities have huge influence in our culture. We still have to ask questions, sometimes very difficult ones. It would be much worse to write gossip items about the unscripted events in their lives without them having a chance to have their say. But we need to make it clear that a deadline is not an ultimatum.”

Wilson and Agruma are now adjusting to the enormous media attention on their relationship. The actor announced the relationship on Friday with a post hashtagged #loveislove, declaring that she had previously thought she was “searching for a Disney Prince”.

“But maybe what I really needed all this time was a Disney Princess,” she said.