The hotel in Bodo, Norway, is where WikiLeaks' missing associate Arjen Kamphuis was last seen on August 20. After three weeks police said his personal effects have been found by a fisherman in the waters of a fjord.

Oslo (AFP) - Personal effects belonging to a Dutch WikiLeaks associate who went missing in Norway three weeks ago have been found in a fjord, Norwegian police said Wednesday.

A fisherman found the objects floating in the water late Tuesday, police said in a statement, confirming the items “belong to the missing person” but providing no details about them due to the ongoing investigation.

Arjen Kamphuis, a 47-year-old cyber security expert, was last seen on August 20 leaving his hotel in the northern Norwegian town of Bodo, where he had been on holiday.

The objects were found near Kvaenflaget, some 50 kilometres (30 miles) east of Bodo, in the waters of a fjord. Police and emergency crews have now begun searching the water and land in the area.

The disappearance, described as “strange” by WikiLeaks, has sparked numerous conspiracy theories on social media.

Police said they were examining three theories: a voluntary disappearance including a possible suicide, an accident, or a crime.

“We haven’t made enough progress in the case to be able to eliminate or confirm any of these three theories,” inspector Bjarte Walla told AFP. “We are keeping all options open.”

A friend of Kamphuis, Ancilla van de Leest, told AFP there were “absolutely no signs he wanted to disappear.”

“Quite the contrary, he made many plans, privately and professionally.”

According to investigators, the Dutchman is believed to have taken a train from Bodo to the town of Rognan on August 20.

WikiLeaks has previously said he had a ticket for a flight on August 22 departing from Trondheim, a town located more than 700 kilometres south of Bodo, but he did not board the plane.

Adding to the mystery, a phone linked to Kamphuis sent a signal in an area near the southwestern city of Stavanger, located 1,600 kilometres from Bodo, late on August 30, police said, but they could not confirm if it was Kamphuis who had switched the phone on. German and Dutch SIM cards were used that day.

Two Dutch investigators have been in Norway since Monday to assist in the search for Kamphuis, who in photos circulating on social networks can be seen wearing glasses with half-long blond hair and a thin beard.

Van de Leest said the ties between Kamphuis and WikiLeaks have been “strongly overblown in the press.”

“He helps organisations with infosecurity advice,” his friend said.

Julian Assange, a founder of WikiLeaks, has been holed up at Ecuador’s embassy in London since 2012 when he was granted political asylum as he feared extradition to the United States to face trial over WikiLeaks’ publication of secret US military documents and diplomatic cables in 2010.