Nazi art hunter James Palmer has no problem ruffling the feathers of powerful billionaires, secretive European banks and anyone else holding a painting that was stolen during World War II.
Some 200,000 pieces of art are believed to have been looted under the Third Reich, and the battle to return those items to their rightful owners has put Palmer in the trenches since 1993.
Reclaiming art stolen by the Nazis is an intensive, protracted and complex affair, and sometimes the fight will get dirty.
Palmer was attacked as a "Holocaust hustler" and "art ambulance chaser" following a bitter dispute with arguably the most powerful art dealing family in the world.
The high school name calling, as Palmer labels it, came last year as the battle over Seated Man With a Cane, a painting by Amedeo Modigliani thought to be worth $30m, reached fever pitch.
Palmer's company Mondex, which specializes in recovering stolen art and unclaimed bank accounts and estates, believed it had irrefutable evidence that art dealer and Jewish billionaire David Nahmad knew the Modigliani he owned had been looted.
Nahmad, whose vast family collection includes 300 Pablo Picasso works, has always denied he would deal in stolen art.
Sensationally, in December last year, The Toronto Star produced a still taken from French TV documentary, claiming to show a small, yellowing label on the back of the Modigliani.
Details of the name and address of the owner appear intentionally scratched and smudged. The documentary makers enhanced the faint writing that was visible, rendering the name "Stettiner".
Palmer, who is working on behalf of the Stettiner estate, was emphatic.
"It was clear the defendant knew this painting was stolen," Palmer told Nine.com.au.
Earlier this month, Palmer claimed a painting by Russian artist Wassily Kandinsky, owned by a German bank and hanging in a Bavarian public gallery, was stolen during the war years.
It is believed The Colourful Life (Das Bunte Leben) is worth $104m. Court papers have been filed and a legal challenge is underway.
Palmer told Nine.com.au he believes there are 100,000 stolen art works are yet to be recovered, mostly scattered throughout Western and Eastern Europe and in North and South America.
He has taken on work for several Australian clients. One family in Australia who he approached to advise they were heirs to a piece of looted art thought he was a Nigerian scammer, Palmer said.
Palmer's team of Nazi art hunting sleuths are comprised of almost two dozen international lawyers and researchers, working across international borders and navigating multiple judicial systems.
Once a dossier of compelling evidence that indicates a painting was stolen is built they contact the owner.
"Often people are surprised, genuinely surprised, to learn that a work of art that they've had in their home for years, sometimes decades, was stolen from someone.
"Almost everybody that we communicate with recognizes that returning something or coming up with a solution is the right thing."
Palmer said he doesn't necessarily feel sorry for people who receive a letter from his company advising them the piece of art they love and think they own could be stripped from their possession.
"I think people have a responsibility when they buy a work of art to know its provenance," Palmer proclaimed.
"What I am seeing often [in my work] is that there is a gap of provenance in the war years, and a reasonable person would be nervous about buying something like that."
Palmer likened it to buying a gold Rolex from someone off the street "You wouldn't do that. And the people who do that take a risk."
To further his point, Palmer refers back to Modigliani's Seated Man With a Cane.
"There is a glaring provenance gap in the war years so any layperson would not touch that painting."
Palmer's unique role offers a fascinating insight into the moral decisions humans choose to make when sometimes millions of dollars are at stake.
"I think on some sort of primal level maybe we are programmed to acquire things.
"People or organisations that have anger or fear something missing could choose to hang onto something no matter what, to the point they are being irrational."