The Court of Arbitration for Sport has upheld WADA's appeal of the AFL anti-doping tribunal's Essendon verdict, with 34 past and present Bombers players banned for 12 months, which means they will miss the entire 2016 season.

The club confirmed the ban on Tuesday morning.

"Regrettably we can confirm the Court of Arbitration for Sport has found 34 past and present players guilty of committing an anti-doping rule violation," club chairman Lindsay Tanner said in a statement.

"As a result, the players - including 12 currently listed with Essendon - have been suspended for the 2016 season.

"The club is currently digesting the decision and we will provide a further update later today."

Last March, the tribunal found the 34 were not guilty of using a banned substance thymosin beta-4, relating to the club's 2012 supplements program, led by controversial sports scientist Stephen Dank.

ASADA, who had brought the case, chose not to appeal the decision, but WADA exercised its right to appeal, leading to a hearing in Sydney last November.

Former Bombers coach James Hird condemned the CAS decision, labelling it as a "miscarriage of justice for 34 young men".

The CAS decision was backed by ASADA, with its chief executive Ben McDevitt describing the saga as an "unfortunate episode".

There are currently 12 of the original 34 still on the books at Essendon - including captain Jobe Watson and vice-captain Dyson Heppell.

List of current players banned for 12 months ESSENDON Tom Bellchambers Travis Colyer Dyson Heppell Michael Hibberd Heath Hocking Cale Hooker Ben Howlett Michael Hurley David Myers Tayte Pears Brent Stanton Jobe Watson AT OTHER CLUBS Jake Carlisle (St Kilda) Stewart Crameri (Western Bulldogs) Jake Melksham (Melbourne) Angus Monfries (Port Adelaide) Patrick Ryder (Port Adelaide)

The other current players affected are Michael Hurley, Cale Hooker, Michael Hibberd, Brent Stanton, Travis Colyer, David Myers, Tom Bellchambers, Heath Hocking, Ben Howlett and Tayte Pears.

Watson and the now-retired Dustin Fletcher will reportedly serve bans eight days longer than the remaining players as a result of playing for Australia in the 2015 international rules series.

Five other players are at other clubs - Paddy Ryder and Angus Monfries at Port Adelaide, Stewart Crameri with the Western Bulldogs, Jake Carlisle at St Kilda and Jake Melksham at Melbourne.

Port Adelaide released a statement expressing its support of Ryder and Monfries.

"Clearly, we are extremely disappointed with today's outcome and in particular we are devastated for Angus and Paddy who have been through so much already," Power general manager of football Chris Davies said.

"This has been a long, drawn out process for both of them and we are most unhappy that it has ended with such a significant suspension.

"First and foremost, we will look to support Angus and Paddy in every possible way during their time on the sidelines.

"We are very proud as to how Angus and Paddy have handled this whole process and as a club we will stand by them all the way."

WADA released a statement confirming the basis of the bans.

"The appeal filed by WADA against the Australian Football League (AFL) Anti-Doping Tribunal's decision of 31 March 2015 is upheld and the appealed decision is set aside," the statement read.

"The 34 players concerned are sanctioned with a period of ineligibility of two years, commencing on 31 March 2015, with credit given for any individual period of ineligibility already served.

"Thus, most of the suspensions will come to an end in November 2016."

Decision brings justice for clean athletes, says WADA

In a later statement, WADA responded to the decision, commending CAS for its verdict.

"While today's decision represents the right result for the anti-doping community, it most importantly represents justice for clean athletes in Australia and worldwide," WADA director-general David Howman said.

"This case shows that analytical and non-analytical evidence gathered through an investigation can be successfully presented to an independent panel.

"WADA is pleased that the CAS panel upheld the standards of proof set out under the World Anti-Doping Code.

"If the AFL Tribunal's decision had prevailed, it would have set a damaging precedent for future non analytical anti-doping cases; and, therefore, been detrimental for anti-doping efforts worldwide."

WADA said that the CAS panel found "to its comfortable satisfaction" that clause 11.2 of the 2010 AFL anti-doping code had been violated, and found by a majority that "all players were significantly at fault".

The verdict also raises questions over the 2012 Brownlow Medal victory of Essendon skipper Watson.

The three-year saga has led to a number of senior figures leaving Essendon, including the former chief executive Ian Robson, former chairman David Evans and his replacement Paul Little, and Hird.

Hird was banned for 12 months in 2013 when the AFL fined the club $2 million and kicked the Bombers out of that year's finals series.

Hird returned after the conclusion of his ban, but he resigned in August last year to allow the Bombers to have a fresh start under a new coach.