STOCKHOLM -- WikiLeaks founder Julian Assange asked Swedish police on Tuesday to investigate what happened to a suitcase he suspects was stolen from him by intelligence agents as he traveled from Sweden to Germany in 2010.
The suitcase contained three laptops with WikiLeaks material, including evidence of a "war crime" allegedly committed by U.S. troops in Afghanistan, according to an affidavit that Assange's lawyer filed along with a criminal complaint to police at Stockholm's Arlanda Airport.
In the affidavit, Assange suggested that the bag "may have been illegally seized "as part of an intelligence operation with the purpose of gathering information about me."
He offered no proof but said all attempts to locate the bag had failed.
The move comes a day before President Barack Obama visits Sweden.
WikiLeaks spokesman Kristinn Hrafnsson said similar complaints would be filed in other countries, including Germany and Denmark, alleging potentially unlawful U.S. intelligence operations against Assange.
"It's time to confront it and fight back on all fronts," Hrafnsson told the AP.
According to the affidavit, the "medium-size soft suitcase with tan color, trolley wheels and an extendable handle" disappeared when Assange traveled from Stockholm to Berlin on Sept. 27, 2010.
"The suspected seizure or theft occurred at a time of intense attempts by the U.S. to stop WikiLeaks' publications of 2010," Assange said, and suggested that Swedish authorities "seek explanations" from members of Obama's delegation during their visit this week.
The police border control division at Arlanda Airport opened an investigation as a matter of course after receiving the complaint Tuesday, spokeswoman Jessica Fremnell said.
She declined to comment on Assange's suggestion to interrogate people in Obama's entourage, saying "we make our own decisions about what we think we need to do."
Assange's lawyer, Per Samuelson, told the AP that airport personnel in Berlin and Stockholm had not been able to locate the bag and could not explain how it got lost.
"It was checked in and we have luggage tags and everything," he said. "It's gone without a trace."
WikiLeaks has published tens of thousands of pages of secret U.S. diplomatic and military communications over the last few years, deeply angering the Obama administration. U.S. Army Pvt. Chelsea Manning, previously known as Bradley Manning, was recently sentenced to 35 years in prison for giving U.S. government secrets to WikiLeaks.
According to Assange's affidavit, the missing suitcase contained evidence of a "massacre" of civilians by U.S. military forces in Garani, Afghanistan.
A U.S. Army investigation concluded that a 2009 airstrike killed 26 civilians, at least 78 Taliban fighters and five Afghan police in the village of Garani. Local officials said the attack killed 140 villagers. It was not immediately clear that this was the event Assange was referring to.
At Manning's court-martial, prosecutors tried unsuccessfully to connect Manning to an encrypted Garani video placed in December 2009 on the computer of a Brookhaven National Laboratory worker.
Assange's affidavit also accuses U.S. military intelligence of monitoring his "journalistic activities" while he attended a conference in Berlin in December 2009 and using that surveillance to assist the prosecution of Manning.
Assange has been holed up for more than a year at Ecuador's Embassy in London to avoid being extradited to Sweden on sex crimes allegations.