Undercover sting reveals how the politician bought hundreds of overseas homes on a $13,000-a-year salary.

Bangladesh’s former Land Minister Saifuzzaman Chowdhury spent more than $500m on luxury real estate in London, Dubai, and New York but did not declare his overseas assets on his Bangladesh tax returns, Al Jazeera’s Investigative Unit (I-Unit) has revealed.

The I-Unit went undercover in the UK to investigate how the 55-year-old Chowdhury, from a powerful family in the port city of Chittagong, amassed a property empire despite a $12,000 annual limit as part of the nation’s currency laws on the amount a citizen can take out of Bangladesh.

Dr Shahdeen Malik, an advocate of the Supreme Court of Bangladesh, told Al Jazeera that the country’s constitution clearly states that politicians must declare their foreign assets.

Authorities in Bangladesh have frozen his bank accounts and are now investigating claims Chowdhury laundered millions of dollars into the UK.

Chowdhury had been a close ally of removed Prime Minister Sheikh Hasina who fled Bangladesh in August after hundreds were killed as security forces cracked down on student protests.

After Hasina’s departure, Bangladesh authorities launched an investigation into allegations of widespread corruption in her government.

The central bank of Bangladesh has since frozen the bank accounts of the former Land Minister Chowdhury and his family, while the state’s Anti-Corruption Commission has started an investigation into allegations that he had illegally acquired “thousands of crore taka” (hundreds of millions of dollars) and laundered it in the UK.

The I-Unit investigation revealed that Chowdhury was able to buy 360 homes in the UK alone since 2016.

Anti-money laundering laws consider high-ranking politicians and government officials to be a high corruption risk as their wealth could be stolen state funds or bribes paid to obtain government contracts.

London estate agent Ripon Mahmood introduced Al Jazeera’s undercover reporters to a network of London advisers that helped Chowdhury to build his property empire: Charles Douglas Solicitors LLP, which acted for him in refinancing more than 100 property loans; Paresh Raja, who made hundreds of loans through his company Market Financial Solutions and his other businesses; and Rahul Marde, of Singaporean bank DBS, which also lent money to the minister.

As a high-ranking politician, he would have been classified as a politically exposed person (PEP) and would have required extra scrutiny and stringent checks when dealing with estate agents, banks, lenders and lawyers in the UK.

In response to the findings, Chowdhury told Al Jazeera the funds used to buy his overseas properties come from legitimate businesses outside Bangladesh which he has owned for years.

Chowdhury fled Bangladesh in August and claims to be the subject of a politically motivated “witch-hunt” against people associated with the previous government.

Charles Douglas Solicitors LLP, Market Financial Solutions, Paresh Raja, DBS Bank and Ripon Mahmood told Al Jazeera they had carried out robust anti-money laundering checks on Chowdhury. They also said his funds came from legitimate and longstanding businesses in the United Arab Emirates, the United States and the UK, not Bangladesh.

The advisers say that the recent events in Bangladesh was not information available to anyone conducting historic Anti-Money Laundering or Know Your Customer checks, which are standard procedures for financial institutions.

Al Jazeera’s Investigative Unit goes on the trail of The Minister’s Millions to find out how Chowdhury built his half-a-billion-dollar property empire.