Police in Vietnam have arrested three senior former bankers and six securities officials over a fraud worth millions of dollars at a partly state-run bank, government media reported Wednesday.

The arrests are the latest scandal to hit the ailing banking sector, which authorities have vowed to clean up after years of bad debts.

The fraud was alleged to have taken place at MHB Bank, which has since been merged into the larger fully state-run Bank for Investment and Development of Vietnam, state media said.

Two of those detained were MHB Bank's former chairman and its CEO, People's Police newspaper online said.

All nine are accused of "abuse of power and rights when performing public duties", punishable by up to 15 years in jail.

The detainees allegedly used capital from the bank to trade in government bonds and shares for their own profit, the report said.

"Investigators found their acts caused losses of millions of dollars to state capital," it added.

The report did not say when the arrests were made. The officials were sacked from their posts before being taken into custody.

Vietnam's economy in 2015 grew at its fastest pace in five years boosted by strong exports, record foreign investment and buoyant domestic consumption.

But economic progress is vulnerable due to high public debts, huge but inefficient state-owned enterprises and rampant official corruption.

Communist Vietnam has been struggling for years to clean up its vast state-run sector.

After the collapse of state shipping giant Vinashin in 2008, the government ordered all state enterprises to divest from non-core investments, but many have still not complied.

There have been a string of recent high-profile arrests of wealthy businessmen and executives over allegations of corruption, embezzlement or incompetence.

In July last year police arrested the former chairman of state oil giant PetroVietnam over mistakes that allegedly led to the loss of a $38 million investment in Ocean Bank. The troubled lender had been taken over by the government after being rocked by a major scandal of its own.

Ocean Bank's former chairman, Ha Van Tham, once one of Vietnam's richest businessmen, is now in detention, pending trial for violations of lending regulations, including approving millions of dollars of loans without proper collateral.