Coleen Rooney has described messages Rebekah Vardy and her agent Caroline Watt exchanged about her as "evil".
Mrs Rooney gave evidence on day five of the High Court libel case brought by Mrs Vardy, who denies leaking private information about her to the Sun.
The court previously heard the pair had allegedly called Mrs Rooney "attention seeking" and a "nasty [expletive]".
However, Mrs Vardy's barrister last week claimed that she had been referring to someone else.
"The messages that went on between them were just evil and uncalled for," Mrs Rooney said on Monday.
"There's no need for it, I've never done anything to them," she continued, adding that she had never met or spoken to Ms Watt, who is not well enough to give evidence in the trial.
Last week, Mrs Vardy denied discussing with Watt on WhatsApp the possibility of using the anniversary of Mrs Rooney's late sister's death as a reason to contact her after she unfollowed her on Instagram.
Mrs Rooney previously said the pair's exchange had "knocked me sick" when hearing it read out in court.
Mrs Vardy's libel action was sparked by a viral social media post from October 2019, in which Mrs Rooney said she had carried out a sting operation to find out who had been passing private information about her life to the Sun.
She said the fake stories she had posted on Instagram in an effort to find the perpetrator had only been viewed by "Rebekah Vardy's account".
Mrs Vardy has continually denied leaking the stories in question to the press. She became tearful last week in the witness box recalling online abuse she and her family had received since the allegation.
On Monday, Mrs Rooney said her suspicions that Mrs Vardy was responsible for leaking stories about her had been raised after Mrs Vardy messaged her asking why she had been unfollowed on Instagram.
Mrs Rooney said that "added to the suspicions that I had" that Mrs Vardy was responsible for information being passed to the press.
In his cross examination, Mrs Vardy's lawyer Hugh Tomlinson put it to Mrs Rooney that Mrs Vardy had contacted her after she made her sting operation public, and that his client "makes it clear to you that it [the leak] wasn't her, doesn't she?"
"She [Mrs Vardy] says she has zero interest in what's going on in my life, which I believe is totally untrue," Mrs Rooney replied.
"She talks about me a lot... so that was a lie."
Mr Tomlinson noted how Mrs Rooney's now famous post had led to people calling her "Wagatha Christie".
"Yeah, which I just think is ridiculous," Mrs Rooney responded. "I got a lot of people sending me pictures, screenshots and obviously people didn't realise how serious what was behind it was.
"I felt it was hard and people I trusted and people I had let into my circle were going against me."
When Mr Tomlinson suggested she had revelled in the attention garnered as a result of the investigation, Mrs Rooney said she had "hated every minute".
She added that she had not spoken to anyone about her sting operation until deciding to go public, not even her husband, former footballer Wayne, or her brother and social media manager Joe McLoughlin (the co-publisher of the now famous post), who later confirmed this himself in the witness box.
After the weekend pause, Mrs Rooney told the resuming court she had wanted a "totally untrue" story about a so-called gender selection procedure in Mexico, which she had planted on Instagram, to be published in the press, as it would give her "evidence" in her sting operation.
Mrs Rooney, the court heard, was alerted by her PR at the time, Rachel Monk, that the Sun was planning on running the story, which the newspaper did four months later.
"I felt that would be an extra step if the papers run it, I would have my actual story in the paper," Mrs Rooney said
"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."
Giving evidence, Ms Monk said she told a journalist from the Sun that the gender selection story was "bonkers".
Mrs Rooney has said she suspected Mrs Vardy to be leaking private stories to the Sun due to her alleged close relationship to the newspaper - she believes Mrs Vardy contributed to the Secret Wag column, which Mrs Vardy denies - and her sense the claimant was "fame hungry".
In week one of the trial, Mrs Vardy, who is married to Wayne Rooney's former England teammate Jamie, denied having moved seats during an England match at Euro 2016 in order to be photographed close to Mrs Rooney.
Harpreet Robertson, a former ticketing manager and family liaison officer for the Football Association (FA), told the court on Monday she believed Mrs Vardy made a "choice" to sit in seats behind Mrs Rooney, which had been reserved for her and FA colleagues.
She said Mrs Vardy's claim that they were the only seats available was "simply untrue", and in her witness statement noted how two of Mrs Vardy's guests that day had been "rude and abusive" to her when asked to move.
Mrs Vardy left court early for the day, with her team saying she had another appointment to attend.
The trial continues, with Wayne Rooney expected to testify on Tuesday.
Read more about what happened in week one of the trial