The federal Environment Minister, Malcolm Turnbull, is reported to be using his travel allowance to pay $175 a night to cover rent when he is in Canberra where he stays at a house owned by his wife.

Mr Turnbull told the ABC TV's Insiders program has defended how he uses his allowance, saying every MP is entitled to the same allowance regardless of where they stay.

"I am entitled to an amount for every night I spend in Canberra," he said.

"Where I stay, whether I stay in expensive accommodation, or in cheap accommodation, in my own apartment or an apartment belonging to my wife, in a hotel or a serviced flat is immaterial, you get the same amount and where you stay is of no concern to the Government."