Anti-corruption police have smashed an illegal bookmaking ring in Hong Kong which is suspected to have used “privileged information” from Jockey Club employees, including two assistant trainers.

The powerful Independent Commission Against Corruption (ICAC) announced the bust on Monday night, saying they arrested a total of 21 people in “operation Iron Triangle” which commenced on Saturday.

A total of six licensed Jockey Club staff members were arrested, with four stable staff joining the two assistant trainers.

ICAC stated that 15 people were operating the underground “corrupt and illegal” bookmaking syndicate from a residential premises in Tsuen Wan with the assistance of the six Jockey Club staff members.

In a statement, a ICAC spokesman said its investigation into the matter had not yet finalised.

“A total of 21 persons, including two assistant trainers and four stable staff of the Hong Kong Jockey Club (HKJC), were arrested for suspected corruption in relation to the provision of privileged information to facilitate illegal bookmaking and control of race horses,” the statement said.

“The HKJC has rendered full assistance to the ICAC during its operation. The ICAC and the HKJC do not tolerate any corrupt activities. The two organisations will continue to liaise and cooperate closely to combat related crimes and keep horse racing in Hong Kong clean.”

In a statement released late on Monday night, the Jockey Club said they have a “zero tolerance” for any illegal acts.

“The club does not comment on any cases being investigated by ICAC. However, the club would like to emphasise that upholding uncompromising integrity has always been the core value of the club,” the statement said.

“It has zero tolerance for any illegal acts or activities of its employees. The club has and will continue to work closely with ICAC in its investigations.”

The Jockey Club has previously revealed at the Asian Racing Conference that it believes illegal gambling is growing at twice the rate of legal turnover.

“The tsunami of illegal betting has arrived,” security and integrity chief Martin Purbrick said.

“Administrators must recognise the risk from illegal betting that threatens racing integrity and collaborate to educate regulators and government agencies.”

It is believed that around US$140 billion is laundered through illegal betting markets each year.

ICAC investigations into racing are nothing new, with the most recent one coming last year when Australian jockey Nash Rawiller was questioned after being found guilty by the Jockey Club of accepting money or gifts in return for race tips and disqualified for 15 months.

After being detained for 48 hours and having his passport confiscated for over four months, the ICAC opted not to charge Rawiller with anything and he was allowed to fly home.

A similar situation occurred with fellow Australian Chris Munce in 2007, but he was sentences to 30 months in jail after being found guilty of selling tips after an ICAC investigation.

One of the most famous scandals came in 1986 when the ICAC broke open the “Shanghai Syndicate”, a race-fixing operation orchestrated by textile tycoon Yang Yuan-loong.