Ostapchuk has been handed a retrospective four-year ban, which ends on August 14, 2016, after she tested positive for the banned steroid metenolone after pipping Adams for gold at the London Games in 2012.
Tests last year of samples the Belarusian gave at the 2005 world athletics championships, where she won gold, also found traces of the steroids formestane and 4-hydroxytestosterone.
Her ban will virtually rule her out of the 2016 Olympics with the suspension due to end during the athletics competition in Rio, though Adams' manager Nick Cowan said they felt the Belarusian had deserved a life ban for a second offence.
"Our understanding is that Ostapchuk has tested positive twice for drugs," Cowan told Radio New Zealand. "You would normally expect that you could face a life ban.
"To be honest we were expecting for it to be a bit heftier than four years but it is what it is."
Cowan said he had only been made aware of the ban on Wednesday after Ostapchuk's name appeared on the latest list of banned athletes issued by the world governing body International Association of Athletics Federations.
They were not told of the process or reasoning, he said.
Athletics New Zealand also expressed their surprise at the length of Ostapchuk's ban but would need to review the decision.
"Whilst Athletics New Zealand is not comfortable with a ban of only four years for two doping breaches, we need to understand the full decision and all aspects that relate to the decision and the four year ban," chairperson Annette Purvis said in a statement.
The 29-year-old Adams, who was promoted from silver to gold after Ostapchuk tested positive in London, has been heavily critical of the Belarusian for 'stealing her Olympic moment' and her anger had not abated on Wednesday.
"Four years is not enough..WTF!!! Oh well, it doesn't change what I do tomorrow!!! #drugcheat #belarussians," Adams said on Twitter.
The four-times world champion, who won her first Olympic title in Beijing, leaves New Zealand on Thursday for her training base in Switzerland. Her next meeting will be the Diamond League event in Doha on May 9.
- Sports & Recreation
- Addiction & Substance Abuse
- world athletics championships