Unregulated mobile payments systems could put consumers at risk for fraud, according to Consumers Union.

The Yonkers, N.Y., advocacy group on Tuesday called on lawmakers to take steps to ensure that consumers are protected when using any of the emerging services that enable them to make purchases with smartphones. These services may open the door to consumer losses through fraud and mismanagement because many are not covered by existing consumer protections, Consumers Union said.

"Many new mobile payment services that are emerging or being tested in the U.S. are not necessarily covered by the type of consumers protections available through a traditional credit or debit card, which is a source of concern to us," Michelle Jun, a staff attorney for Consumers Union, said in an interview.

Federal laws protect consumers if their credit or debit cards are lost, stolen or misused, but current protections are "badly fragmented" and do not necessarily extend to all types of emerging mobile payments, Jun said.

Prepaid cards may pose additional risks because few provisions exist for resolving disputes with merchants, she said.

So far, Consumers Union has not seen broad examples of consumer fraud from mobile payments, but there will be increasing opportunities for consumers to be exploited as mobile payments gain momentum, Jun said.

The group is "hopeful" that the Consumer Financial Protection Bureau, established when President Obama signed the Dodd-Frank Act into law last month, will help regulate mobile payments.

"Although it's early in the process, and the consumer protection bureau is not yet up and running, we hope that providing consumer protections for mobile payments is one of the roles it will assume," Jun said.