"Due to the ongoing police investigation the IBU Secretary General has requested a leave of absence from her role(s) within the IBU," the document read.
Executive Director Martin Kuchenmeister will serve as the acting secretary general as Resch decided to step down, the press release noted, adding the the IBU is taking the situation very seriously.
The IBU Executive Board is cooperating with the investigation, the statement pointed out.
James Fitzgerald, senior manager for media relations at the World Anti-Doping Agency (WADA), said on Wednesday, that the investigation concerning the IBU was related to doping.
"WADA confirms that the issue is linked to doping, but we do not want to comment further," Fitzgerald said as quoted by the Norwegian NRK broadcaster.
Other Norwegian media reported earlier in the day, that raids as part of the probe into the IBU had taken place in the country.
On Tuesday, the Austrian Federal Criminal Police carried out a search at the IBU headquarters in Salzburg as part of the probe, the IBU statement read.
The doping scandal erupted when the WADA accused Russia of multiple violations of anti-doping rules and suspended the Moscow laboratory of the Russian National Anti-Doping Agency (RUSADA). In 2016, Richard McLaren, head of the WADA investigative team, presented a two-part report alleging the existence of a state-supported doping program in Russia. Russian officials have refuted the allegations but admitted that Russian sports have had some doping-related issues.
The situation resulted in the International Olympic Commission imposing a lifetime ban on a number of Russian athletes, the revision of the 2014 Olympics results, as well as the disqualification of the Russian national team from the 2018 Winter Games in South Korea. Only "clean" athletes from Russia were allowed to participate in this year's Olympics, under a neutral flag.