Just after 11pm, Celtic manager Neil Lennon took to Twitter to say: "Thats the window shut for another while...looking forward to seeing the players in the morning."
Earlier, he'd told followers: "Contrary to reports there have been no fresh bids for Gary and even if there are they will be rejected..he is NOT for sale."
The Scottish champions have rejected three bids from Norwich for their top scorer, who has 23 goals so far this season.
Reports today claimed fourth and fifth offers had been tabled by the Canaries in an attempt to test Celtic's resolve.
However, the Hoops were determined to hold onto one of their key players ahead of their Champions League last-16 meeting with Juventus.
Elsewhere in the Clydesdale Bank Premier League, business was taking place as clubs bolstered their squads.
Aberdeen confirmed the signing of Mark Reynolds on a four-and-a-half-year deal, after the Sheffield Wednesday defender made his loan move permanent.
The deal sees him remain at Pittodrie until summer 2017, while goalkeeper Dan Twardzik has signed an 18-month contract after being granted international clearance.
Reynolds said: "After a spell of uncertainty, it's great to get my future sorted out and know that I'm going to be in the north east for the foreseeable future.
"My family settled in Aberdeen very quickly and we really like the area and, with the recent birth of our son Lucas, it's a huge boost to know that we'll be staying here.
"It's up to me to repay the faith the club has shown in me and I do believe we have a squad capable of bringing success to Aberdeen."
Twardzik was also thrilled with his switch to the Granite City.
He told the club's website: "After spending a week here earlier in the season, I made up my mind that this was the place I wanted to come to.
"I was delighted when the club approached me on Tuesday evening and said that they wanted me."
St Johnstone could yet take a second Newcastle player on loan until the end of the season.
Winger Marcus Maddison could complete a temporary switch to the Perth club tonight, following midfielder Medhi Abeid in swapping Tyneside for Tayside.
Saints have also secured teenager Gwion Edwards on loan from Swansea until the end of the season, while confirming they have parted company with long-serving midfielder Kevin Moon by mutual consent.
Newcastle defender Paul Dummett has returned to St Mirren after agreeing another loan deal until the end of the campaign.
Bottom side Dundee signed Nottingham Forest midfielder David Morgan on loan for the rest of the season in a bid to boost their SPL survival hopes.
Hearts did not add to their squad on transfer deadline day - but they did secure three young players on extended contracts.
Scotland Under-21 midfielder Dale Carrick has signed until summer 2014, left-back Kevin McHattie - who has made 10 starts this season - signed a two-year deal, while Scotland Under-19 goalkeeper Jack Hamilton put pen to paper for another year.