BANGKOK (AFP) - Thai police have broken up the country's biggest loan shark syndicate with nationwide raids on a network of creditors who circulated some four billion baht (US$111 million) to tens of thousands of debtors, authorities said Friday (Dec 23).

Thailand is wracked with high levels of household debt and unscrupulous lenders are notorious for preying on the poor with exorbitant interest rates.

On Friday Thailand's justice department said it had cracked down on a 2,000-strong gang of black market creditors who had distributed some four billion baht to 170,000 borrowers across the country.

"Based on the investigation, the network was established in 2011 and has 86 branches," said Charnchao Chaiyanukij, the Justice Ministry's permanent-secretary, adding that the lenders charged up to 300 per cent in annual interest.

Investigators believe that more than 1,000 state officials had assisted the gang in some capacity, he added.

Authorities have frozen 28 bank accounts and seized 14 safes stocked with cash, 26 cars and 86 motorbikes in a series of nationwide raids.

Yet only one suspect - the gang's IT chief - is in custody.

The racket's kingpin is believed to have fled the kingdom earlier this week, Charnchao said.

Thailand's household debt has surged to alarming levels in recent years, surpassing more than 80 per cent of the kingdom's GDP.

Much of the money is borrowed from loan sharks who target low-income Thais with limited access to formal credit and no assets to use as collateral.