The BSA also condemned Campbell Live for secretly filming Harkema in two highly offensive breaches of her privacy.
"TV3 accepts that Campbell Live's allegations were wrong, and unreservedly apologises to Ms Harkema for the damage caused to her reputation and the severe distress caused to her and her family," last night's voiceover said.
The message is also on TV3's website.
A Mediaworks spokesman refused to comment further last night.
In February last year, the BSA ordered the show to pay Campbell Live broadcaster Mediaworks $12,000 towards Harkema's legal costs and $2000 compensation for the privacy breach.
It said the show "hyped up" aspects of an investigation into Harkema.
The authority said it was "inevitable" Harkema would have attracted criticism for her involvement with an animal testing facility.
"She did have a position of responsibility in the company that undertook the commercial business of animal testing."
Yet allegations against her were overblown and breached standards of fairness and accuracy.
"It drew inferences that were not able to be drawn and generally hyped up the items to a point beyond where they ought to have been."
Harkema complained of a privacy breach related to a hidden camera sting showing her delivering beagles to a prospective buyer.
The authority said there was not enough public interest in the particular footage captured to justify covert filming.