GENEVA (AP) - Swiss authorities investigated several reports of terrorist financing among a high number of suspected money-laundering cases connected to banks last year, federal police said on Tuesday.

The number involving terrorist financing rose to 15 in 2012, five more than a year earlier, due to a single complex case of almost US$8 million (S$9.91 million) , according to an annual report issued by the Money Laundering Reporting Office in the Swiss capital Bern.

According to police, there were 1,585 "suspicious activity reports" for 2012 involving $3.3 billion, slightly less than the amount in 2011.

A third of the cases were reports of fraud.

For both years, two-thirds of the cases were linked to banking. The rest were mainly tied to payment services, fiduciary and asset managers.

Though the number of cases was high in 2012, the police said, they were not characterized by any exceptional political circumstances like the political upheaval in 2011 that swept across North Africa and the Middle East.

Six reports alone accounted for $1.5 billion.

Three of those involved the suspected misappropriation of foreign public funds, police said, while two were connected to suspected document forgery and fraud and one concerned an alleged crime group from Asia.