Lauren Greenfield’s film about the Philippines’ former first lady Imelda Marcos reveals a grotesquely self-pitying, wholly unrepentant and very rich woman, who has clearly still kept her hands on a great deal of the American aid money that successive US presidents once gave the Philippines in return for suppressing communism and civil rights and showing hospitality to US naval power – cash that she and her husband, Ferdinand, looted from the public purse and salted away abroad.

This was the larceny that finally got them booted out of office and briefly exiled in the 80s, but Imelda returned to her homeland as a widow, and is now trying to create a gruesome Marcos dynasty, led by her idiotic son, Ferdinand Jr (nicknamed “Bongbong”), and another daughter, Shee. They are minor politicians who are, to cite the TV show Succession, the Kendall and Shiv of this story, with waxy hatchet-faced Imelda very much the Logan Roy figure.

One of the most purely objectionable figures anywhere in the world … Imelda Marcos. Photograph: Lauren Greenfield

The Marcoses’ patent mediocrity and corrupted brand identity appear to have put serious political power out of reach for them, for now. But their resurgent cynicism and corruption created the conditions for Rodrigo Duterte, the quasi-fascist strongman president who is shown contemptuously tolerating the Marcoses for what they could yet do for him.

It seems at first as if this is going to be simply a black-comic portrait of entitlement, comparable to Greenfield’s 2012 film The Queen of Versailles. Actually, it is more than that: a larger, tragic picture of tyranny and corruption in the Philippines that might stand alongside Josh Oppenheimer’s The Act of Killing (2012) and The Look of Silence (2014) about the repression and slaughter in Indonesia.

There are exquisitely horrible moments in this portrait when Marcos, taking us around her fabulous Manila home, and speaking in an absurdly queenly and soft-voiced way about her lifestyle and her plans for the future, unknowingly reveals how loathsome she is. Or perhaps she does know and doesn’t care, and has a shrewd sense of how her outrageousness plays well with a certain part of her (sizeable) fanbase. But it is truly stomach-turning as she gives banknotes to poor little children in the street and, on being taken to a children’s cancer hospital, Madame Marcos winces with disgust at their poverty and suffering and says to an aide: “Give me some money to give away.”

Briefly, we are taken through her history: she was the former beauty queen who enjoyed a whirlwind romance with Ferdinand, the ambitious young politician. Once in power, Ferdinand was content to let Imelda go abroad to meet foreign leaders – there is an emetic shot of Mao kissing her hand. This was because he feared leaving the country in case he was toppled in a coup, and also wanted to pursue extramarital affairs. When Imelda discovered these, a certain hardness entered in her soul, making it even harder than it already was.

At their height, the Marcoses took the cash intended for roads, schools etc and converted it into jewels, paintings and prime Manhattan real estate, while striking brutally at civil rights, using detention and torture. Their rival, Benigno Aquino, was imprisoned, exiled and finally murdered, and his widow, Cory, was later to take over as president herself. There are wrenchingly emotional interviews with those who were detained and tortured under the Marcos regime. A grisly symbol of the corruption is the bizarre wild animal reserve that Imelda created on Calauit Island, a vanity project that involved moving hundreds of families off the land, and whose giraffes are now not properly cared for – like everyone and everything else.

For all that Marcos has to be one of the most purely objectionable figures in public life anywhere in the world, she is not a fool and occasionally reveals shrewd insights about herself. She notes how cordially she was received internationally and smirks: “Sometimes it helps that you are not taken too seriously.” Later, with regard to her blandly conceited image management, she remarks: “Perception is real, but the truth is not.”

• The Kingmaker is released in the UK on 13 December.