Liza Minnelli was “forced” to appear in a wheelchair against her will at last month’s Oscars, a longtime collaborator has claimed.

Michael Feinstein, a singer and pianist and friend of Minnelli has said that her appearance at the end of the ceremony, in which she presented the best picture award alongside Lady Gaga, left her “very disappointed”.

“She only agreed to appear at the Oscars if she would be in a director’s chair, because she’s been having back trouble,” said Feinstein on Tuesday, speaking on SiriusXM’s The Jess Cagle Show.

“She said, ‘I don’t want people to see me limping out there.’ She said, ‘You know, I want to look good. I don’t want people to worry about me.’”

Minnelli and Gaga’s presentation of the best picture prize to Coda provided a relatively calm close to a show overshadowed by events an hour or so earlier, when Will Smith slapped presenter Chris Rock on stage.

This disruption had “shaken up” the organisers, claimed Feinstein, leading them to abruptly change the plan for Minnelli. According to Feinstein, a stage manager informed her just minutes before her appearance that she’d be seated in a wheelchair rather than a director’s chair.

It is not known whether Minnelli was originally supposed to be wheeled on to stage and then transferred to the chair during an ad break or whether she was intended to walk with aid to the chair.

“She was nervous,” said Feinstein, “and it made her look like she was out of it. Can you imagine being suddenly forced to be seen by millions of people the way you don’t want to be seen? That’s what happened to her.”

Earlier this year, Feinstein and Minnelli duetted on Embraceable You for Feinstein’s latest album, Gershwin Country.

Gaga and Minnelli won praise from audiences and critics for their warm and collaborative turn. The pair have been close for more than a decade, and last month Minnelli’s former publicist Scott Gorenstein told People their appearance at the Oscars was at the direct request of Gaga.