The ABC’s budget for local drama, Indigenous, documentary and children’s TV has been quietly shrinking since 2013 as management siphons off millions of dollars into other areas of the public broadcaster, according to the former head of ABC TV Kim Dalton.

In an essay published on Monday Dalton said ABC management and boards were ultimately not called to account for diverting money from Australian content.

Dalton ran ABC TV from 2006 to 2013. In his essay, Missing in Action: the ABC and Australia’s Screen Culture, he has blamed the absence of transparency in the ABC’s allocation of funds to different areas – such as news, digital, radio, regional and management – as well as a lack of public discussion or public policy.

He said the ABC was underfunded, but sheeted the blame home to management rather than budget cuts by successive governments.

“Whatever the size of the reduction, it is significantly larger than the cuts imposed on the ABC by the Abbott government and at least in part it preceded them,” Dalton said.

Dalton said the ABC was given additional funds by the Rudd government to establish a children’s channel on the promise it would broadcast 50% Australian content. However, the level of Australian content on ABC Me had already dropped to 25%.

Dalton said the ABC held up its independence as a way to avoid scrutiny of how it chooses to allocate its global budget, handed down every three years.

“The ABC can bask in positive reviews for Redfern Now, only to quietly shift money away from Indigenous drama a few years later,” Dalton wrote.

“There is little or no consistency or transparency around the reporting of any of this. Furthermore, the government has no mechanism whereby it monitors or establishes requirements for the ABC’s performance in regard to its Australian content or its engagement with the independent production sector.”

Dalton was particularly scathing about the ABC’s commitment to children’s television under managing directors Mark Scott and Michelle Guthrie, saying the institution had “never internalised the idea that children’s television was important”.

“Children’s programming is just not in the DNA of the ABC,” he said.

Kevin Rudd launched Australia’s first free TV channel for school-aged children, ABC3, in 2009, after an injection of $67m in the budget. It was rebranded as ABC Me in September.

In the early days it produced award-winning Australian drama including My Place and Dance Academy, as well as the children’s news show Behind The News.

But within four years the ABC was reallocating these funds, Dalton said. “While Labor was still in power up to a third of the budget had been transferred out of children’s.

“Further cuts have been imposed in the years since: the ABC also quietly halved its Australian content objective from 50% to 25% and with fewer funds the children’s department has inevitably been commissioning a less diverse slate,” he said.

“Ultimately, in the absence of commitment from individual senior managers, children’s TV is not prioritised. The institutional commitment is absent and now, just a few years later, this brief period [of ABC3] is beginning to look like a golden era that was all too soon over.”

Dalton said despite earlier efforts to increase levels of documentary and drama at the ABC, including tied or allocated funding from governments, after 2013 these areas were no longer a priority.

“In the 2013–14 budget an estimated 10% of the documentary budget was reallocated and further cuts were made in budgets that followed. By 2016 the ABC was broadcasting only one history documentary, the two-part Howard on Menzies: Building Modern Australia.”

Dalton said the ABC now commissioned no natural history programs where it once commissioned six to eight a year, and its commitment to Indigenous content had fallen after two series of Redern Now.

“Ultimately, this was a decision of senior ABC management endorsed by the ABC board to de-prioritise the commitment that had been made to the development of an Indigenous prime-time drama strand and to reallocate the funds elsewhere within the ABC.

“Few would disagree that the ABC’s editorial independence must be preserved, protected and where necessary vigorously defended,” he said. “It is what distinguishes a public broadcaster from a state broadcaster.

“However, the ABC is also a public institution established by parliament and funded by the taxpayer. It is Australia’s major cultural institution and the public interest in its services and its operations rightfully extend to its engagement with, and its impact on, the country’s cultural output and its creative capacity.”

The ABC declined to comment.