Organised crime gangs are operating in and running refugee accommodation across Sweden, according to Sveriges Radio (SR).
Criminal gangs were found to have infiltrated refugee accommodation in all seven of the country's police regions, intelligence sources told the broadcaster.
Last year Sweden received more refugees per capita than any other European country, with 163,00 applying for asylum in the Scandinavian nation of 9.8 million people.
The West, North, Bergslagen and Central regions all reported criminal activity at refugee accommodation. The Central region featured the highest number of residencies where criminals had a presence.
The Swedish police National Operations Department's (NOA) head of intelligence, Linda Straaf, said the organised crime gangs were involved in procurement for refugee accommodation, and there were fears that they would seek to exploit vulnerable refugees.
"Examples are prostitution, or taking advantage of people in vulnerable positions through illegal labour," she said.
The Swedish government estimates 40 billion Swedish crowns ($4.8 billion; £3.2 bn) will be spent on immigration and integration, four percent of the country's 2016 budget. In 2015, 60 new contractors started competing with the 150 in existence for the 1.4 bn krona paid out to provide emergency accommodation for refugees.
In January, police were criticised for failing to cope with rising crime at refugee centres, after 22-year-old refugee centre worker Alexandra Mezher was stabbed to death by a 15-year-old boy at a refugee centre in Gothenburg. Police said they urgently needed up to 2,500 new officers to cope with the demands of securing borders, deporting failed asylum seekers, and responding to reports of crime in refugee centres.
In January Europol revealed that at least 10,000 unaccompanied child refugees had gone missing after arriving in Europe, and warned that vulnerable minors were being targeted by criminal gangs. In Sweden alone, 1,000 children remained unaccounted for.