WASHINGTON — A planned trip by former President George W. Bush to Switzerland this week has been canceled in the face of threatened large-scale protests and calls for an investigation into whether his administration committed human rights abuses in the fight against terrorism.

A spokesman for Mr. Bush said Saturday that the trip was canceled after the United Israel Appeal, an international Jewish charity organizing the Geneva event where he had been scheduled to speak next Saturday, told him on Friday that it was canceling the speech because of security concerns.

“We regret that the speech has been canceled,” said David Sherzer, a spokesman for Mr. Bush. “President Bush was looking forward to speaking about freedom and offering reflections from his time in office.”

The visit to Geneva was to have been Mr. Bush’s first trip to Europe since his memoir, “Decision Points,” was published in November, and the first since he publicly stated in interviews on his book tour that he had personally authorized the use of waterboarding in the questioning of terrorism detainees.

As a result, international human rights groups, including Amnesty International, seized on the scheduled visit to petition the Swiss authorities to open an investigation of Mr. Bush while he was in the country. The groups argued that he had admitted to torture and thus could be prosecuted in Switzerland and other countries that have signed on to the international convention banning torture.

“For a long time at Amnesty International, we have been calling for the Obama administration to investigate human rights abuses at Guantánamo, the C.I.A. black sites, and in Iraq and Afghanistan, and it is clear that’s not happening,” said Widney Brown, Amnesty International’s senior director for international law and policy. “When we heard that he was traveling to Geneva, we wrote to the national authorities in Switzerland and the local prosecutor in Geneva to ask them to investigate Bush for torture.”

Amnesty International sent Swiss authorities documents detailing their case for prosecuting Mr. Bush for torture, based on his admissions and other evidence concerning the waterboarding of two members of Al Qaeda, Khalid Shaikh Mohammed and Abu Zubaydah.

Swiss officials told human rights groups recently that they had no plans to try to prosecute Mr. Bush, Ms. Brown said. But the prospect of large demonstrations at the site of Mr. Bush’s speech remained, and the event’s organizers feared that protests could turn violent. Protest organizers were said to have asked demonstrators to carry shoes to the event, recalling how an Iraqi journalist threw a shoe at Mr. Bush in 2008 to protest his visit to Baghdad.

While Mr. Bush does not face any legal sanctions in Switzerland, this is not the first time officials from his administration have faced the threat of legal action in Europe for involvement in possible human rights abuses in the war on terror. Prosecutors and judges in several European countries, notably Spain and Germany, have in the past proved willing to pursue long-shot international legal cases against foreign leaders based on war crimes evidence, and in recent years some of them have turned their attention toward Bush administration officials.

In 2009, for instance, a Spanish court began a criminal investigation of six former administration officials, on grounds that they had violated international law in connection with the military prison at Guantánamo Bay. The Obama administration was apparently so concerned about the investigation that it pressured the Spanish government to make sure the case was derailed, according to State Department cables made public by the antisecrecy group WikiLeaks.

As early as 2005, Donald H. Rumsfeld, the secretary of defense at the time, faced the threat of war crimes prosecution in Germany over human rights abuses at Abu Ghraib prison in Iraq. Eventually, German prosecutors decided not to pursue the case, but only after Mr. Rumsfeld publicly said that he might not attend an international defense conference in Munich because of the legal threat he faced.