Two Japanese were detained by Italian financial police last week after trying to enter Switzerland with $134 billion worth of undeclared U.S. bonds, mostly Treasury bonds, an Italian newspaper reported Wednesday.

The Japanese Consulate General in Milan acknowledged that two people had been detained, but it was still trying to confirm with Italian authorities their identities and whether they are Japanese nationals.

According to the report in il Giornale, two unidentified Japanese in their 50s concealed the bonds, including 249 U.S. Treasury bonds worth $500 million each, in a suitcase with a false bottom. The bonds were found June 3 during a search by Italian authorities in Chiasso, on the border with Switzerland about 50 km north of Milan.

The newspaper did not say on what grounds the two were detained, but they may have been held on suspicion of attempting to take a large amount of securities out of Italy without declaring them.

It said the Italian authorities were investigating whether the securities are genuine, given their huge value.

If the bonds are genuine, the two could be fined around 40 percent of their total value, it said.