$4.5bn was allegedly misappropriated from the Malaysian state investment fund and used to buy luxury real estate, expensive works of art, and even to produce a Hollywood movie about, of all things, financial fraud.

But how did they do it?

According to the US Department of Justice, one strategy involved setting up bank accounts under fake company names that resembled real firms.

BlackRock Commodities (Global) Limited sounds a lot like the global investment manager, while Affinity Equity International Partners Limited could easily be mistaken for the private equity firm.

There's no law against this, but it could help put investigators off the scent.

Another scheme saw money transferred to trust accounts at US law firms.

Client confidentiality rules in the US mean these accounts are barely regulated, making suspicious transactions difficult to find.

The DOJ alleges that firms like Shearman and Sterling and DLA Piper were unwittingly used to sneak a billion dollars from 1MDB into the US.

The third strategy allegedly employed is what the DOJ calls layering; moving funds from bank account to bank account, adding layers of complexity, until the original source of the funds is camouflaged.

Let's follow the money allegedly used to buy this pink diamond necklace for Rosmah Mansor, the wife of former Malaysian prime minister and founder of 1MDB, Najib Razak.

It all starts with a $3bn bond arranged by Goldman Sachs in 2013.

That was issued by a wholly-owned subsidiary of 1MDB incorporated in the British Virgin Islands, and the proceeds were earmarked for a joint venture with a firm in Abu Dhabi.

But instead of heading to the Middle East, most of the money was transferred into an account at Swiss private bank BSI, in Lugano.

From there, the DOJ claims it was shifted to investment funds in offshore centres.

The money was wired by a correspondent bank account at JPMorgan Chase in the US to two accounts at the Singapore branch of Swiss private bank, Falcon Bank.

Funds went back and forth between these accounts, adding layer upon layer of complication, gradually obscuring the origin.

Eventually, $681m were transferred from Tanore into a Malaysian bank account held by Najib Razak, a sum he insists was a political donation from the Saudi royal family.

Five months later, most of it was returned.

The money bounced around accounts at Falcon and DBS Bank in Singapore before a sum of $27.3m was, according to the DOJ, wired to jeweller Lorraine Schwartz to buy the necklace.

The complexity of these cross-border flows has made getting to the bottom of the 1MDB fraud painstaking and difficult.

But with Malaysia's government keen to burnish its graft-fighting credentials and claw back the money stolen, the investigation shows no signs of slowing down.