A prolific, self-published romantic fiction novelist has been exposed as a plagiarist after a reader spotted that she had switched the gender in a tale of romantic suspense to turn it into a gay love story.

Becky McGraw, a New York Times bestselling writer, was alerted by one of her readers about the similarities between her own novel My Kind of Trouble, in which Cassie Bellamy falls for bad boy Luke Matthews when she returns to her hometown of Bowie, Texas, and Laura Harner’s Coming Home Texas, in which Brandon Masters falls for bad boy Joe Martinez when he returns to his hometown of Goldview, Texas.

“She emailed to ask if I’d started writing gay romance under a pen name,” said McGraw, whose editor subsequently reviewed both books, and highlighted the similarities. These have also been extensively detailed online by novelist Jenny Trout; Trout has provided screenshots and extracts from both books, and writes that “Harner’s clever trick here was to pick a book that was not M/M [male/male], but M/F contemporary romance. As far as readers go, there isn’t a lot of overlap between the two genres.”

McGraw writes: “Since she’d gotten the call from Imelda, the closest thing to a mother that Cassie had known since her own mother died when she was ten, Cassie had been in that mode. Once she decided she needed to come back, the memories she thought she buried ten years ago would not leave her alone. Thoughts of Luke Matthews would not leave her alone.”

Harner, whose Amazon profile says she has written more than 50 novels and sold almost half a million books, writes: “Since he’d gotten the call from Isabella – the closest thing to a mother that he’d known since his own mom died when he was nine – Brandon seemed to be stuck on a never ending sentimental highway. Once he decided he needed to come back, the memories he thought he buried long ago wouldn’t leave him alone. Thoughts of Joe Martinez won’t leave me alone.”

“Her book was almost a word-for-word, scene-for-scene duplication of my book, except the characters’ names had been changed, and short M/M love scenes had been inserted,” said McGraw. “The only scene she didn’t include was the epilogue, which couldn’t be altered to an M/M scene. It involved the heroine in labour and the hero having sympathetic labour pains.”

McGraw is intending to take legal action against Harner, who has pulled the book from retailers since McGraw first posted about the situation on Facebook, along with her Deuce Coop series, which was revealed to be similar to Opal Carew’s Riding Steele novel, again a straight romance turned into a gay one. The similarities were laid out in a second blog post by Trout, who wrote that “it’s almost impressive how much Harner was still able to plagiarise from Carew here, given the fact that the characters are of mostly different physical and clothing descriptions”.

Responding to the Guardian in a statement, Harner said she realised she had “made mistakes”. “I own them, and I will deal with the consequences. In transforming two M/F romance stories into an M/M genre, it appears that I may have crossed the line and violated my own code of ethics,” she wrote.

“For those who know me best, you know that responsibility for my actions begins and ends with me. I will also add there are some personal and professional issues I’ve had to deal with in the last year that have stretched me in ways that haven’t always been good for me. I write about certain concerns related to military service for a reason; however, I am not offering that as an excuse. I just think whenever someone acts so out of character, it’s helpful to ask why.”

Harner added that she was “working to address concerns raised by two authors who have accused me of plagiarism”, saying that she would provide a more complete statement later this week. “Until then, please do not judge me too harshly.”

McGraw, however, urged other romantic fiction novelists to check Harner’s backlist to see if they recognise their work. “Considering that Laura Harner, AKA LE Harner, has ‘written’ in seven or eight genres in five years, started series in those genres, and published 75 books so far in that span of time, I’d say everyone in every genre needs to be concerned, both indie and traditionally published authors,” she said.

Trout added that there was “definitely shock” about the situation, but that she was “surprised that there isn’t more shock from authors”. She pointed to “this unwritten law in the world of romance, young adult, and new adult authors and readers. I call it Be Nice, in which every author is expected to be supportive and enthusiastic of every other author, regardless of bad behaviour. And a lot of authors exploit Be Nice to do really awful things to each other, because they know they’re not going to be called out.”

The only way, Trout said, that plagiarism will be taken more seriously “is if readers are willing to call it out when they see it, without making excuses for it or saying, ‘it’s OK, because I like this plagiarised version more’, which does happen, and if authors are willing to stand up for other authors.

“When someone takes something from you, you sort of look around to see if anyone else notices it, if they’re going to be on your side if you say something. And most of the time, the answer you get is that no one wants to be involved. So authors stay silent and hope it goes away, or they’re advised by their publishers or agents to just ignore it and Be Nice. Until there isn’t incentive for people to plagiarise, until there are actual consequences to their actions, then it’s never really going to stop.”