The TAB says the cyber attack that crashed its website several times in the past two days has been brought under control.
It said it does not know who is behind the attacks and there has not been anything like it before.
Executive general manager, Glenn Patrick, told Summer Report the attack was flooding the website with bogus requests.
He said the agency itself was able to block the requests but in doing so, the site appeared to be down to customers.
Mr Patrick said staff are working around the clock to fend off the attacks and the Cyber Security Centre will investigate and
police have been informed.
The kind of attack made on the TAB's website over the past two days is very simple to organise but hard to defend a cyber protection expert says.
Mark Shaw, a technology strategist for Symantec, a company that helps protect businesses' information, said he expects it could be a denial-of-service attack.
He said in order to prevent such attacks, businesses need to work out how to allow customers through to their websites, while blocking traffic from bad sources.
Mr Shaw said it was hard to say whether a group or individual was behind the attack.