Steven Avery's fiancée, Lynn Hartman, told Dr. Phil in a special that aired Monday that she has no doubts he loves her

By Lindsay Kimble
Updated October 03, 2016 05:55 PM

Making a Murderer subject Steven Avery‘s fiancée, Lynn Hartman, discussed their atypical romance during an interview that aired Monday on Dr. Phil – just hours after a source told PEOPLE the pair have already split.

Echoing many of the same comments she shared with PEOPLE last week, Hartman told Dr. Phil McGraw that she and the convicted murderer are in love.

“I truly love Steven with all my heart and I know without a doubt he feels the same about me,” Hartman, 53, said in part one of the two-part special.

However, hours before Hartman’s interview aired Monday, a source close to Avery’s family told PEOPLE that his relationship with Hartman is “over already.” Hartman’s interview segments for the show were taped before the break up, the source said.

Avery, 54, is behind bars for the 2005 murder of 25-year-old Wisconsin photographer Teresa Halbach, though he has always maintained his innocence – the subject of the popular Netflix series.

The pair got engaged over the phone in the early hours of Sept. 6 – months after communicating initially through friendly letters.

Of their early phone conversations, which began a month after Hartman sent the first letter, Hartman told McGraw, “I felt instantly like we’d known each other forever, and that obviously stems from the fact that I had the opportunity to watch the [series]. … I felt an instant connection because I felt like I kind of already knew him.”

The Las Vegas legal secretary said at the end of their first call, Avery told her he loved her – a sentiment she first perceived to be customary in the Avery family.

“I took it that way at first, but the more we wrote and talked, the more he told me he truly did love me,” she shared with McGraw.

Of the surprising marriage proposal, Hartman explained, “I felt like, ‘Yes, I think that my life has prepared me for this moment and this journey that I’m about to go on. So my answer was yes.’ ”

RELATED VIDEO: Do Steven Avery’s Neighbors Think He’s Guilty or Innocent?

Flash-forward to now and the pair has split after mounting tensions between Hartman and Avery’s family and their suspicions of her motives, the Avery source claimed to PEOPLE.

(Reached Monday, Hartman declined to comment on the split.)

In fact, Avery and Hartman have not spoken since taping their segments for Dr. Phil, the source said, speaking on the condition of anonymity.

When Avery does try calling his fiancée, “the number is blocked,” the source claimed.

The source added that Avery’s family thinks that Hartman is “trying to cash in by doing interviews, and now she’ll do even more about the break up.”

Hartman told McGraw in the Monday special that she wouldn’t normally be attracted to Avery – “but after getting to know him, it’s a different story.”

Part two of Hartman’s Dr. Phil interview airs Tuesday.