The 31-year-old failed a drugs test following their 36-8 defeat by Wakefield Trinity on 14 July.
The Super League club said they had received notification from UK Anti-Doping and the Rugby Football League.
A Widnes statement said: "The club fully respects this suspension and are currently reviewing this matter."
Chase won the Man of Steel award in 2011 - a year in which he would later go on to represent England and earn eight caps.
He joined Widnes from the Tigers in May, initially on loan, before the deal was made permanent in July.
BBC Sport's rugby league correspondent Dave Woods
Rangi Chase has been the ultimate enigma since he arrived at Castleford eight years ago. Unbelievably skilful, he has produced some of Super League's most breathtaking moments.
But equally breathtaking has been his often off-field stupidity. His has been a career full of official warnings, last chances and shown doors by a collection of clubs that have lost patience with his extra-curricular activities.
He's come and gone at Cas, Salford, Leigh, Cas again and now, presumably, Widnes. If this latest drug test failure is upheld, there will finally be no way back in rugby league for his mercurial, magical but misguided talents.
Precedent has been set. Gareth Hock, then at Wigan, was banned for two years when he was found guilty of cocaine misuse ahead of a game.  If the same holds for Chase, that would take him to 33. Age alone would probably be against him. But reputation will hold even greater sway.
A premature end to his career, if that's what this is, will surprise no-one but it will sadden many that such skills, such sublime ability that he possesses couldn't have been harnessed for the even greater pleasure of all those who have marvelled at the very best of Rangi down the years.

6 October 2015 Last updated at 08:13 BST
The nine-day event will host more than 500 balloons, representing 20 different countries.
Thousands of visitors are expected to enjoy the spectacular sights.

The app is the latest development by Mikeysline, a charity set up following the deaths of two friends.
Michael "Mikey" Williamson and Martin Shaw, who were both 23 and living in Inverness, were found dead within days of each other in October last year.
Family and friends fear the young men took their own lives.
Mr Williamson was found dead only hours after returning from a night out to remember his friend Mr Shaw.
Launched in December last year, Mikeysline already offers support via text messages and is staffed by volunteers.

Matt Tubbs' sixth goal of the season came from the spot on 70 minutes for Ryan Astles' challenge on Yemi Odubade.
Chester, who had beaten Aldershot 8-2 in midweek, were completely overrun by an Eastleigh side who had lost five of their previous seven league matches.
Visiting keeper Tony Thompson denied Luke Coulson, Josh Payne and Odubade before Tubbs' deserved winner.
The fight to reach the play-offs remains tense, with Eastleigh now only two points behind fifth-placed Braintree, while Chester are only eight points clear of trouble.
Chester manager Steve Burr told BBC Radio Merseyside:
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"There were two things we felt hard done by. We had a goal disallowed in the first half when Ryan Higgins cut the ball back to Ross Hannah.
"And the lads are unhappy with the penalty decision. There was minimal contact. It was harsh, to say the least
"They have a very expensively assembled side with experience, who you could see are used to playing on that pitch and, in the end, it was settled by a penalty
"It was always going to be tough after what has happened this week, then the long journey down. We set off at seven o'clock this morning and you could see one or two tired legs out there. But I don't want to make excuses. We didn't create enough chances."
Widnes Vikings half-back Rangi Chase has been suspended from all training and playing activity after testing positive for cocaine.
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The 44th annual Albuquerque International Balloon Fiesta is under way in the US.
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A smartphone app designed to help young people who are dealing with depression and suicidal thoughts has been launched in Inverness.
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Eastleigh secured back-to-back wins for the first time since December as they narrowly defeated Chester.