Embattled political duo Don Nardella and Telmo Languiller have been accused of electoral fraud, as the fallout from the Labor entitlement scandal deepens.

Parliament's internal auditors found that Mr Nardella had registered to vote at an Ocean Grove property and Mr Languiller had registered at Queenscliff, despite little evidence from either to justify that the towns were their principal place of residence.

The two western suburbs MPs have caused outrage by moving their home base to the popular beachside towns and claiming an entitlement designed for country MPs who are forced to visit Melbourne.

Mr Languiller has repaid nearly $38,000 in claims but Mr Nardella is refusing to repay any money. He has claimed at least $113,000 for living in Ocean Grove, well away from his Melton electorate.