A former Olympic official who fled Russia after President Vladimir Putin criticised him for delays and cost overruns before the 2014 Winter Games in Sochi claims he has been poisoned.

Akhmed Bilalov, fired as deputy head of the Russian Olympic Committee in February, said on Saturday that doctors had discovered elevated mercury levels in his blood. He is receiving treatment in Germany.

"They have found elevated levels of mercury in my body," Bilalov told the Interfax news agency, confirming Russian press reports. "I didn't want to announce this before, but now that the press has found out, I'm forced to confirm it."

Bilalov was axed after Putin toured Olympic sites in the southern city of Sochi a year before the launch of the Games. Amid widespread reports of construction delays and cost overruns, the president singled out Bilalov for a public dressing down over an unfinished ski jump at Roza Khutor, the cost of which had ballooned from 1.2bn to 8bn roubles (£24.8m to £165m). Video footage of Putin ridiculing Bilalov quickly went viral.

Bilalov, a native of the republic of Dagestan, was subsequently stripped of his positions, including as head of a state-owned company building ski resorts across the Caucasus region. He fled the country shortly after.

In April, a criminal case was opened against Bilalov for allegedly misspending more than £60,000 from the state company, including for travel to London during the 2012 Olympics. Prosecutors are also investigating him for allegedly embezzling £1.7m from the company.

The former Olympic official said he believed the source of the mercury was his office in central Moscow. He told Interfax he "began to feel bad in the middle of autumn last year", adding that he felt satisfactory after receiving treatment.

According to Gazeta.ru, an online news portal that saw a copy of Bilalov's medical report, the former official is at a clinic in Baden-Baden. Doctors found four times the normal amount of mercury in his blood. A source close to Bilalov told Gazeta that other employees at his Moscow office were being tested. "Everyone is in shock," the source said.

Bilalov said: "I don't want to blame anyone or speculate on how the mercury appeared in my Moscow office. I have no idea. Upon returning to Moscow, I plan to approach law enforcement agencies so they can help sort out this situation."

With less than a year until the launch, the Russian event has been fraught with scandal and controversy. The budget has swollen to five times original estimates and, at $51bn, it will be the world's most expensive Winter Games. Allegations of corruption, worker mistreatment and environmental damage have also surfaced.