Australian lawmakers Thursday backed calls for a full judicial inquiry into media ownership, at the end of their own year-long investigation sparked by a record-breaking petition demanding a probe into Rupert Murdoch's dominance of the sector.

The Senate committee recommended the establishment of an independent and more "comprehensive investigation" that could subpoena witnesses and look at overhauling media watchdogs.

"Australia has one of the most concentrated media markets in the world", the lawmakers found, with a regulatory regime that is "not fit-for-purpose".

"Large media organisations have become so powerful and unchecked that they have developed corporate cultures that consider themselves beyond the existing accountability framework," their report said.

It is unlikely that the incumbent conservative government, which usually enjoys strong support from the Murdoch press, would act on the Senate recommendations.

However, they could have a greater chance of success if the centre-left opposition Labor party takes control at upcoming elections due by May next year.

The Senate investigation was prompted by a petition by former Labor prime minister Kevin Rudd -- a frequent target of newspapers controlled by Murdoch's News Corp -- that attracted half a million supporters.

The Australian arm of the New York-headquartered company is the country's largest media organisation, owning papers in nearly every major city as well as cable television networks and magazines.

Rudd, who was prime minister from 2007 to 2010 and briefly in 2013, has long been critical of what he has called the media organisation's "vicious" campaigning for the political right.

He welcomed the Senate report Thursday, calling it an "important decision" for the future of media ownership and regulation in Australia.

The committee also called for Australia's public broadcasters, ABC and SBS, to receive better funding, along with independent newswire Australian Associated Press, which nearly collapsed when investors including News Corp withdrew support in 2020.