(Cover) - EN Showbiz - Justin Timberlake apparently had an early hours visit to Scarlett Johansson's home last week.

The singer was on a night out with Scarlett on September 14 at New York City hotspot 1OAK.

The pair have known each other a long time and Scarlett even appeared in the music video for his 2007 hit What Goes Around Comes Around.

But the twosome were "hardcore flirting" during the evening and very cosy together, an eyewitness told Us Weekly.

"Other guys were trying to talk with Scarlett, but she was only focused on Justin."

The pair partied until dawn and were seen leaving the venue at 5.30am and going next door to get a pizza.

Justin is then said to have gone to the Iron Man 2 star's penthouse apartment where the singer introduced himself as "Justin" to the doorman.

He apparently "wasn't even low-key" about the visit. Representatives for both stars have denied that the early morning visit happened.

But a pal told the publication that Justin and Scarlett have "hooked up several times over the years".

Justin has reportedly recently got back together with his on-again, off-again girlfriend Jessica Biel after splitting earlier this year. (C) Cover Media