Coleen Rooney has told the High Court she wanted a “totally untrue” story about a so-called gender selection procedure to be published as “evidence” for her sting operation to discover the source of leaked stories.

In the high-profile libel trial brought by Rebekah Vardy, Mrs Rooney began giving evidence at the Royal Courts of Justice on Friday afternoon, and on Monday morning she returned to the witness box.

In a viral social media post in October 2019, Mrs Rooney, 36, said she had carried out a “sting operation” and accused Mrs Vardy, 40, of leaking “false stories” about her private life to the press – prompting her to be dubbed “Wagatha Christie”.

Mrs Vardy, who is married to Leicester City striker Jamie Vardy, denies leaking stories to the media and is suing her fellow footballer’s wife for libel, while Mrs Rooney is defending the claim on the basis her post was “substantially true”.

The court previously heard that Mrs Rooney said that as part of this “sting operation” she planted three false stories on her private Instagram account, with the viewers restricted to only Mrs Vardy’s account, to see whether they would be leaked to The Sun newspaper.

One of these stories was posted on April 8 2019, with Mrs Rooney claiming she was travelling to Mexico to look into a procedure to determine a baby’s sex.

“Let’s go and see what this gender selection is all about,” Mrs Rooney posted, accompanied with a number of heart emojis and what appeared to be a grimacing face emoji.

Around four months later, The Sun published a story online on August 15 2019 with the headline “Col’s baby girl bid”, marked as an exclusive, detailing Mrs Rooney’s alleged “desperate bid to have a baby girl”.

Asked about this post by Mrs Vardy’s barrister Hugh Tomlinson QC on Monday, Mrs Rooney said: “I wanted the story to run so I had evidence.”

She added: “I felt that would be an extra step if the papers run it, I would have my story and the actual story in the paper.”

Mrs Rooney, who is married to former England footballer Wayne Rooney, continued: “I didn’t want it out there, I wanted it for my own evidence… It was a story that was out there but it was completely untrue.”

The High Court heard that earlier in August, PR Rachel Monk told Mrs Rooney The Sun was planning to write a story on her visiting Mexico over the treatment.

The footballer’s wife explained she told Ms Monk to tell the newspaper that she “can’t get hold of me”.

With The Sun seeking a comment on the story, Mrs Rooney told the court: “I just said don’t comment… so obviously that means they run it or not, it’s up to them.”

“I didn’t say no, I didn’t say yes.”

The court also heard that in March 2019 Mrs Rooney asked Ms Monk to find out who was the source of a story about herself and her husband securing a babysitter, following an approach from The Sun newspaper.

Mrs Rooney told the court she had a suspicion it was Mrs Vardy, telling the PR that she was allegedly “fame hungry” from “stuff she’s done at the World Cup”.

Hearing the accusation of being “fame hungry”, Mrs Vardy, sitting in the front row of Court 13 alongside her solicitors, appeared to shake her head.

Asked why she did not delete Mrs Vardy from her Instagram, Mrs Rooney said she did not want to “trap” her, adding: “I just wanted to find out who was doing this to me.”

“I thought by going public on Instagram and saying someone is doing this to me I thought it would stop,” she said, adding: “But it continued.”

Earlier on Monday, Mrs Rooney told the High Court she “had suspicions” that Mrs Vardy’s Instagram account was responsible for leaking information to journalists when she unfollowed her on the social media site.

The footballer’s wife accepted it would have been obvious to Mrs Vardy in March 2019 when she texted Mrs Rooney that she had been unfollowed.

Mrs Rooney said the pair were “not good friends” and that if someone had unfollowed her she would “probably just forget about it and not message” the person, adding: “I wouldn’t have been that bothered really.”

She said: “I felt it was suspicious. Obviously, I had suspicions in other ways, so this just added to the suspicions that I had.”

Mrs Rooney is defending the libel claim brought by Mrs Vardy on the basis of truth and public interest.

The libel battle comes after Mrs Rooney publicly claimed that an account behind three fake stories in The Sun that she had posted on her personal Instagram account was Mrs Vardy’s.

As well as the “gender selection” post, the fake stories Mrs Rooney planted on her Instagram during the sting operation also included her planning to return to TV, and the basement flooding at her home.

In the post on Instagram, Twitter and Facebook, she wrote: “I have saved and screenshotted all the original stories which clearly show just one person has viewed them.

“It’s ………. Rebekah Vardy’s account.”