OTTAWA - Senators have more paperwork to do as an audit begins into their use of housing allowances to cover the costs of maintaining a home in Ottawa, while also having a home in the province they represent.

The audit will "assess whether declarations of primary and secondary residence are supported by sufficient documentation," according to a Senate news release.

There have been several recent media reports questioning how some senators are using their $20,000 allowances.

A Senate subcommittee is already reviewing allegations raised in a CTV report that Conservative Sen. Patrick Brazeau rarely uses the west Quebec home he's listed as his primary residence.

On Thursday, the bipartisan group was directed to expand its work and review similar concerns about Liberal Sen. Mac Harb.

Conservative senator and former Newfoundland auditor general Elizabeth Marshall chairs the subcommittee that also includes fellow Tory Gerald Comeau and Liberal Sen. Larry Campbell.