The song, an eccentric ode to the US state of Massachusetts, had received 315,000 views by the time it was taken down on Wednesday morning, after it was linked to by influential US sites such as Gawker and Billboard.
Four hours after coming back online, that had risen to 500,000 hits.
"Something has happened to our YouTube account, which we're working to get to the bottom of it," Hanne McBride, a spokesperson for TV Norge, which broadcasts the brothers' show I Kveld med Ylvis, told The Local.
She said that several of Ylvis's YouTube videos had been pulled simultaneously.
"Luckily the Fox is still alive. Obviously it's a bit of a shame, because lots of media has linked to it, and now it's just showing a dead link, and it looks like we've taken it down intentionally."
Bård Ylvisåker said that the song, which was recorded in the summer before The Fox was released, was intended as an answer to a question from a viewer on what the duo did when they were off TV.
"It's about a place we go to in order to charge up our batteries during the off season. A place where we can truly be ourselves and just totally relax," he said.
Before the video was released Bård was quick to downplay expectations.
"We have no commercial aspirations at all," he said. "We cannot create Stonehenge [another YouTube success] every time."
In the song, sung in a sweeping melody over rhythmic guitar, the two celebrate their "favourite place on earth", gradually building up a gang of Massachusetts locals around them, such as a troop of Boy Scout types, a group of catholic priests and a male dance outfit.
The lyrics are below:
Far away across the ocean
An undiscovered paradise
Forget New York and California
There's a better place - now close your eyes
Take my hand - We are almost there
Our favorite place on earth!
It's the 14th biggest state.
Just four hours from New York
Read amazing books for free
At the Boston Library
Or try the local brie
It's a melting pot, my friend
So many cultures hand in hand
In perfect harmony
Welcome to the Massachusetts
Land of a thousand tribes
Home of Nelson Mandela
Fuck the apartheid!
Come on boys of Attleborough
(Hello, hello, hello hello)
Catholic Priests of Haverhill
Staring dogs of the Suffolk County
Local dancegroup of Pingryville
Everyone - Living side by side
In the state of hope and dreams!
I can’t believe this place is real
Can’t describe the way I feel
I live with Steve and John
Mark and Cristopher and Tom
Teddy P and Bruce
The famous Massachusetts Bay
Home of JF Kenneday
That tragically was shot
Just grab a friend and rent a car
drive and drive across the Massachusetts
Just two friends hanging out together
but never crossing the line (it's a thin, thin line)
Oh, were nothing more than friends
(Just good friends!)
Go S and S and O
Go C and H and E and I
Go H and E and I
Go M, A double K
Go A and K and O K O
Doesn’t sound right to me
That's way too many K’s
It should be mass - achoose
Like the “mass” in “massproduce”
But without “produce”
That's the state I’m talking about
Come on down, and you will see
It’s paradise on earth.
Oh - oooh
Yeah, Massachusetts - Paradise on earth
Boston city skyline, or a picnic in the park.
Checking out the nightlife, and suddenly your sucking on a cock, hooo!
Massachusetts, greatest state of all
Just because your kissin’ a man, it doesn’t make you gay
1620 - The pilgrims came to town
Sometimes I watch The Lion King and I cry when Mufasa dies
Prudential tower, City hall and a lighthouse by the bay
Who hasn’t ever seen a hunk on the bus and thought “Mmm, I wanna sit on your lap”.
Oh-oh-oh oh, oh, ooooooh.