Commentator Peter Alliss caused a sexism row by referring to the short skirt worn by golf hero Sergio Garcia's fiancee.
The 86-year-old made the off mic remark about Angela Akins in BBC coverage of The Masters, The Sun reports.
As images were shown of Angela, 31, reacting to Garcia's win, Alliss's muffled voice was heard saying: "She's got the shortest skirt on the campus."
Last night the BBC confirmed Alliss believed he was off air when he made the "lighthearted" comment and accepts it was "inappropriate".
The remark was picked up by viewers who watched the dramatic events on Monday morning, when the Spaniard beat Brit rival Justin Rose to claim his first ever major in 74 attempts.
One member of the TV audience of over 2.5 million called for the BBC to get rid of Alliss immediately saying he "ruined" Garcia's "finest moment" with the "disgraceful comment".
Akins, 31, who started dating Garcia almost two years ago, is a former college golfer who has worked as a reporter on the Golf Channel. They announced their engagement in January and plan to marry in July.
In the closing stages of the battle between Garcia and Rose, Akins was shown by the side of the green cheering on her partner in a baseball cap, grey jogging top, blue skirt and trainers.
A BBC Spokesman said: "Whilst believing he was off air Peter made a lighthearted remark which he now knows was inappropriate."
This is the latest in a string of sexism rows to engulf the long-serving commentator.
In 2015 Alliss made headlines when Zach Johnson won the British Open. As he lined up for the winning putt, the veteran commentator had a go at reading the mind of his wife Kim Barclay.
"She is probably thinking, 'If this goes in I get a new kitchen,'" Alliss said.
In April of the same year Alliss said Harriet Harman's Equality Act, ending men-only tee times and other restrictions placed on females' access to club facilities, had "buggered up" the game because women couldn't afford the fees in.