While Michael Buble was tying the knot last week ... a bunch of scumbag thieves were breaking into his home in Argentina ... this according to several reports.
Buble and his wife Luisana were staying at a resort outside Buenos Aires during the break-in. Luisana's parents and brother spoke with police before the happy couple arrived back from the wedding.
According to reports, the bad guys covered up the security cameras and cut the lines to the alarm system -- though it's unclear what they took from the home.
After learning about the burglary, Luisana told local reporters, "I will not let this ruin the happiest day of my life."
The couple was married on Thursday ... but the celebration lasted all weekend.