Staff at a branch of Afghanistan's central bank in southern Kandahar province may have got away with as much as $1.4m, when they robbed their own bank and escaped, an official said.

Security cameras showed the bank's vault had been cleaned out, but investigators were waiting to gain access before confirming the total missing, the official said on Saturday.

"Yesterday we could only open one of the treasury's doors. We hope to open the next one today," the central bank director for Afghanistan's southwestern region, Fazel Ahmad Azimi, said.

The robbery at the branch in Spin Boldak near the border with Pakistan was discovered on Thursday and investigators believed the group had escaped to Pakistan.

The Kandahar raid is believed to have been carried out by a senior official at the bank, an employee of nine years, with the help of his son and brother-in-law who were also on staff, according to Azimi.

The group had removed CCTV recordings before fleeing to Pakistan, Azimi said, but investigators were hopeful that footage might be recovered from the memory chip of the security cameras.

Weak regulation undermines confidence in Afghanistan's fragile banking system, which has yet to fully recover from a 2010 scandal over a bank that collapsed triggering a financial crisis.

An international financial watchdog last year threatened to place Afghanistan on a blacklist, and has since warned it needs to do more to enforce laws to regulate its banking sector.

Source: Agencies