The anti-money-laundering watchdog is investigating two of Australia's biggest online sports betting companies.

The Australian Transaction Reports and Analysis Centre (AUSTRAC) says it has “reasonable grounds to suspect that Sportsbet and Bet365 may have contravened or are contravening the anti-money laundering and counter-terrorism financing law and rules”.

External auditors have been brought in to assess Sportsbet's and Bet365's compliance with anti-money-laundering and counter-terrorism financing laws.

“AUSTRAC is putting the whole industry on notice to lift their game,” Nicole Rose, AUSTRAC chief executive, said in a statement.

“Ultimately, enforcing non-compliance is about protecting the community.

“Money laundering feeds organised crime and all the harm that comes with it.”

AUSTRAC has given auditors 180 days after their appointment to determine whether both companies have risk-based systems and controls in place to effectively identify, mitigate and manage money laundering and terrorism financing risks.

The audits come at Sportsbet and Bet365's expense.

The regulator is not giving any specific details of the Sportsbet or Bet365 matters, saying it does not want to pre-empt the auditor’s findings and final reports.