The Cocos (Keeling) Islands are a collection of tiny islands on two atolls. Credit:Getty Images Between them, Mr Simpkins and Ms Griggs claimed $5756 in "travelling allowance" during their time on Cocos and Christmas Islands in April last year for two public hearings of the parliamentary inquiry into Australia's administration of its Indian Ocean territories. Air fares for family members to Cocos, a coral atoll of 27 islands with a population of about 600 that bills itself as "Australia's last unspoilt paradise", appear to have been funded under "family reunion" provisions of the controversial parliamentary entitlements system overseen by Finance. The system fell under the spotlight in 2013 when the late Don Randall, a WA Liberal, spent $5000 to fly with his wife on "electorate business" to Cairns where they had bought an investment property. Questions have been raised about the appropriateness of using family reunion to Cocos because travel records suggest Mr Simpkins and Ms Griggs both spent the previous week in their electorates.

Natasha Griggs. Credit:Andrew Meares All family members flew back to the mainland on Monday April 6, a day before the first official engagement of the joint standing committee on the national capital and external territories, of which Mr Simpkins is chairman and Ms Griggs a member. They stayed until April 10, when a VIP Challenger jet operated by the Air Force flew the committee and three staff back to Perth and Canberra at a cost of $35,000. Liberal MP Luke Simpkins. Credit:Andrew Meares

In an emailed statement on Tuesday night, Ms Griggs said: "In April 2015 I undertook an official visit to Cocos (Keeling) Islands in my capacity as a member of the Joint Standing Committee on the National Capital and External Territories. All travel was within the parliamentary travel guidelines." Mr Simpkins did not respond to questions put by Fairfax Media. Finance guidelines state family reunion is there to "balance [MPs'] work and family responsibilities and to reconcile the need for them to be away from home for long periods with their family obligations". "The entitlement is not intended to provide a general travel entitlement for a senator or member's spouse or nominee, dependent children or designated persons," the rules state. Senator Nick Xenophon, a famously frugal traveller on the public purse, told Fairfax Media that he believes family reunion entitlements should be restricted to visits to Canberra for official events.

Two other members of the joint standing committee, Chris Back and Ross Vasta, who did not bring family members with them, flew into Cocos on Tuesday April 7, a day before a public hearing into Australia's administration of the island. Labor MP Warren Snowdon, a committee member whose electorate of Lingiari includes the Cocos islands flew in on April 3 and left on April 6 - two days before the public hearing. Mr Snowdon, who was travelling in his electorate on Tuesday, said he did not bring a family member but would need to consult his diary to recall what appointments he had in Cocos. Promotional material for Cocos says the islands offer "spectacular snorkelling, world-class diving, excellent fishing and the adrenalin-rush of kitesurfing". "The Cocos Keeling Islands are also a deeply tranquil holiday location. Relax on empty beaches, visit uninhabited islands by canoe, watch spectacular birdlife or catch the ferry to Home Island and discover the culture and traditions of the Cocos Malay people."

In its interim report, signed off by Mr Simpkins, the joint committee said it "visited Cocos (Keeling) Islands from 7-9 April 2015 and Christmas Island from 9-10 April 2015". After one five-hour hearing on Cocos and one on Christmas Island, the committee made three recommendations: That the government consider reopening the Christmas Island casino - closed in part due to concerns around problem gambling - that consideration be made to allow fee-paying foreign students into the Christmas Island high school and that the government facilitate cheaper sea freight to the region. The committee's report gives little sign that there were days of engagements on Cocos. "In addition to the public hearings and community statements, while on Cocos (Keeling) Islands the committee undertook inspections on West Island that included the jetty, former quarantine station, waste management facilities, light industry area, sites of erosion and sandbagging. On Home Island the committee visited the school, local brickworks, light industry and residential areas, as well as the CluniesRoss clam export venture," the committee said. "On Christmas Island the committee undertook drive-by inspections of the jetty at Flying Fish cove, a community arts project, a raised sea wall in the Kampong that helps protect the area in monsoon season, and the now no-longer-used immigration detention site at Phosphate Hill. The committee also visited the Mining to Plant Enterprise (MINTOPE) research project and talked to staff at the Christmas Island Recreation Centre."