SYDNEY, AAP – National Australia Bank investors have had a scare from the financial crimes watchdog and helped tip the share market lower.

AUSTRAC said it found potentially serious problems in the bank’s efforts to prevent money laundering and was continuing to investigate.

NAB shares fell 3.16 per cent to $26.64 on Monday.

All the banks were lower and the benchmark S&P/ASX200 index closed lower by 13.5 points, or 0.19 per cent, to 7281.9.

The All Ordinaries closed down by 11.7 points, or 0.16 per cent, to 7531.6.

Casino operators Crown Resorts, Star Entertainment and SkyCity Entertainment were lower after receiving similar messages from AUSTRAC.

The Australian dollar was buying 77.34 US cents at 1629 AEST, higher from 76.61 US cents at Friday’s close.