The 20-year-old was instantly questioned by the Barclays Premier League club who revealed the former London gang member expressed 'regret' over the photograph which has been meet with widespread dismay.
Loony Toon: The picture, which shows the London-born forward wearing a hooded top holding the silver handgun in front of his face, was taken at his home by his girlfriend
'Footballers are an example to young boys,' said disappointed Mothers Against Violence campaigner Patsy McKie, whose son was shot deadin Manchester.
'He probably thought this was a bit of fun, but guns tear people's lives apart.'
Ranger, an England Under 19 international who came on as a substitute during Sunday's 2-2 draw at Stamford Brodge against Chelsea, was pictured with the firearm - said to be a replica - before a night out with his friends, according to The Sun.
The forward from north London had vowed to reform his ways having spent an 11-week period inside a young persons institute as 15-year-old over a mugging.
Speaking previously about his experience, he said: 'I started running with a gang. We were convicted of street robbery in Muswell Hill. There was a weapon but we didn't use it.
Outrage: Nile Ranger has provoked an angry reaction after posing with a gun
'Jail was pretty rough but it taught me a lot. The most important thing I learned is that I never want to go back.
'Coming up to Newcastle has completely changed my life.'
But he let Newcastle down, the club who offered him a footballing lifeline when they rescued him from a life of potential crime in 2008, by posing as a 'gangster' holding the chrome gun.
'The club have spoken to Nile and can confirm that the item shown in the photograph is a replica firearm which is not an offence to own,' a club spokesman told The Sun.
'Nile regrets posing for the photograph, which was taken by his girlfriend at home.'
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