Malcolm Turnbull, Australia's second-richest parliamentarian, has invested in a ''vulture fund'' based in the tax haven Cayman Islands.

Disclosure of what appears to be a $1 million stake in a New York-run fund targeting distressed and bankrupt companies sparked criticism from financial transparency campaigners on Thursday.

Under pressure: Malcolm Turnbull. Credit:Glenn Hunt

They argue the Communications Minister has invested legally but in conflict with the Coalition's current campaign against corporate tax dodging and the offshoring of profits.

Australia is to chair the G20 leader's summit in Brisbane in November and Prime Minister Tony Abbott and Treasurer Joe Hockey have put on the agenda discussion of tax evasion and profit shifting.