Taylor Swift has been spilling the beans on how she got a nice surprise while house-hunting in New York City - finding a Hollywood star in one of the apartments she was viewing.

The pop superstar appears on Alan Carr Chatty Man tomorrow evening - and Channel 4 have given us a preview of the show after it was filmed last night.

And as well as taking an adorable selfie with the host, T-Swift shared the amusing story about how she came to own Lord Of The Rings and X-Men star Sir Ian McKellen's former home.

"So basically, I found this apartment online and was looking at all these different places in New York, and I had my realtor reach out to the realtor who rented this apartment, and we kept trying to get a showing, and they kept putting us off and not responding, so it became like a mystery: why can't we get into this apartment? What's in there? Why do they have it on the market but clearly don't want to sell it?

"And then so, as I do, we just obsessively called - 'Can I see it? Can I see it? Please? Can I see it?'

"And so eventually that worked and I got a showing, and I'm walking in kind of like 'What is the deal?'. I fall in love with the place immediately, and then I walk into the kitchen and Gandalf is sitting at the kitchen counter, in his pyjamas.

"It was magnificent. I was like 'I'm buying it. Does he come with it?'"

The 24-year-old also explained how she had "stalked" a number of her superfans via the web, before inviting them to her house to hear her new album 1989 with her.

"You kind of go on the internet and have a look at their Instagrams, maybe look at what their life is like, like 'cute cat, cute dog', and then I would send in the URL for their Twitter, their Tumblr, to my web team, and they compiled this list of people we were going to contact when the time came.

"So they were contacted, they were told 'meet in a church parking lot at this particular time, we can't tell you any more information other than it's Taylor Swift-related'.

"So then their phones were taken, they were put on buses and didn't know where they were being taken."

To which Carr quipped: "It's like a hostage situation."

And Swift continued: "I know, but they did it – they signed NDAs and stuff, and then came to my house. The first group didn't realise where they were until they were like snooping around and looking inside the windows of the house, and they see like a Grammy on the mantle, and pictures of my friends, and that was when... I was hiding in the bedroom, spying on them.

"I'm not coming off well! I'm coming off really creepy!"

And she revealed that despite having 25 fans to visit her homes, she was only aware of one minor theft.

She explained: "I think, one of the soaps went missing. Because one of them was like 'she doesn't have any soap in her bathroom', and I was like 'well if there's no soap, it's because somebody took the soap'.

"So then I just put all these little soaps in the bathroom, so that if they wanted to take them they could. If you want to take the soaps, then I will make it readily available for you to steal them.

"At least no one's going to go without soap now, I don't want to come off as unclean."

The full interview can be seen on Channel 4 at 10pm tomorrow night (Friday).