Unseeded Wickmayer lost to Caroline Wozniacki in the US Open semis
US Open semi-finalist Yanina Wickmayer has been handed a one-year ban for falling foul of doping regulations.
Wickmayer was suspended by the Flemish Doping Tribunal (VDT) for failing to fulfill the "whereabouts" requirement for drug testing on three occasions.
The Belgian world number 18 has denied any wrongdoing and plans to appeal to the Court of Arbitration for Sport.
Compatriot Xavier Malisse has also been banned for a year over two similar "whereabouts" testing failures.
Malisse could also appeal against the decision but the 29-year-old claims that he does not have enough money to.
"A procedure before Cas is very costly and lasts a very long time," he said.
"I currently don't have the financial means to take on such a battle. I still don't know what I'm going to do, but if the suspension is maintained that means the end of my career."
Under anti-doping regulations, athletes are obliged to tell national anti-doping authorities where they will be at a chosen hour each day for a three-month period.
Wickmayer, 20, had been playing at this week's WTA tournament in Bali but VDT spokesman Koen Uman said the suspension "has immediate effect".
It is a fundamental principle that all of us in tennis share that we want to have a fair and clean sport for all players
WTA Tour chief executive
A WTA statement said: "Belgium's Yanina Wickmayer has voluntarily withdrawn from the Commonwealth Bank Tournament of Champions following reports of the decision of the Flemish Doping Tribunal in Belgium to suspend her for 12 months, effective immediately, due to whereabouts procedural issues."
Wickmayer's spokesman Rudi Kuyl later told a press conference: "We are examining all different options... this news really hit home incredibly hard."
And WTA Tour chief executive Stacey Allaster said: "Because it's an ongoing matter, it's in her best interest to let the matter sit. The decision's been made, and now she'll deal with it with her legal advisers going forward."
Allaster added: "Beginning in 2009, Wada (the World Anti-Doping Agency) mandated that all international Olympic sports federations and the national anti-doping agencies were required to implement the whereabouts program.
"It is a fundamental principle that all of us in tennis share that we want to have a fair and clean sport for all players."
The International Tennis Federation (ITF) said it had not been informed of the suspensions.
It is very hard to come back... in a year's time I will be 30 and a half
"Before we can comment on doping cases until we have been notified in writing by the Belgian anti-doping agency and that has not happened as yet," an ITF spokesman said.
The VDT said in a statement issued on Thursday that the minimum one-year sanction was a "reasonable and justified" punishment.
Wickmayer has enjoyed a breakthrough year in 2009. Unseeded, she reached the last four at the US Open, having never passed the second round at any previous Grand Slam.
She won her first two tour titles at Estoril in May and Linz last month, earning her a spot in this week's season-ending champions event in Bali.
Malisse is a former Wimbledon semi-finalist but has slipped to 95 in the world rankings, having reached a high of 19 in 2002. He has won three titles in his career.
The 29-year-old, who has won three titles in his career, was in tears at a news conference in the northern Belgian city of Antwerp, saying: "It is very hard to come back... in a year's time I will be 30 and a half. I will then have to play Challengers and Futures again. That is something I can't really see myself doing.
"It is hard to get a one-year suspension if you never used doping."