KATY Perry is upset with Taylor Swift just one day after the pair ended their six year feud – because Taylor shared her apology letter on social media, say friends.

Insiders tell The Sun Online that Katy was “surprised” to see her hand written message to Taylor shared online as they hadn’t discussed the letter going public.

4 Taylor Swift posted shared a video of a gift from Katy Perry, including a sweet letter and an olive branch

“Katy expected that Taylor would post something about it, but she didn’t expect the actual letter to go on social,” says her friend.

“The thing is, you can only see part of what Katy wrote and it looks like she’s taking sole responsibility for the entire feud.

“Without context, it looks like she’s taking the blame for everything and obviously there’s a lot more to it than that.”

Last night, on the first night of her Bad Reputation tour, Taylor filmed herself opening a gift from Katy.

4 The singers had previously been friends but famously fell out in 2012 in a row over backing dancers Credit: Getty - Contributor

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As she films the gift, the singer can be heard saying: “I just got to my dressing room and found this actual olive branch. This means so much to me.”

The letter is partially obscured but it appears Katy, 33, has written: "Hey Old Friend — I’ve been doing some reflecting on past miscommunications and hurt feelings between us."

It also shows that Katy says she’s “deeply sorry” about something.

The singers fell out in 2012 after Taylor claimed the Firework singer stole three of her backing dancers from her Red tour.

4 Taylor began her US tour last night Credit: Getty Images - Getty

Two years later, she released the single Bad Blood, which was rumoured to be about the long-running feud after she told Rolling Stone the hit was about another female artist who tried to “sabotage an entire arena tour”.

But she has never publicly revealed who the artist is.

4 Katy sent an actual olive branch to her former enemy Credit: Rex Features

Katy, who recently rekindled her relationship with British actor Orlando Bloom, then appeared to retaliate with the single Swish Swish.

She finally addressed the feud last year on The Thrive Global Podcast, where she said: “I am ready to let it go.

“I forgive her and I’m sorry for anything I ever did, and I hope the same from her … I love her, and I want the best for her. And I think she’s a fantastic songwriter.”

The Sun Online has approached Taylor and Katy's teams for comment.

Taylor Swift ​perfor​ms ​'​I Did Something Bad​'​ on the opening night of her Reputation Stadium Tour

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