Roading contractors work to clear up diesel spills across Hamilton City.

The owner of the bus that spilled diesel across the city has apologised to Hamilton motorists amid a full audit of its fleet.

On Thursday morning, a failed diesel hose clamp on an Orbiter bus caused the mass spill, creating risky driving conditions for morning commuters at peak hour.

Pavlovich Coachlines chief executive Bernard Pavlovich​ said the driver, while at Chartwell, noticed the problem at 6.37am on Thursday.

Phillipa Yalden The route of the bus that spilled diesel in Hamilton.

The failed clamp made the fuel line come loose. The bus was repaired at Chartwell.

A response team was notified immediately, as was the Waikato Regional Council and police, and Pavlovich maintenance staff were dispatched with a replacement bus and a spill kit, working to contain the original spill at The Base while regional council staff worked to contain the spill along the bus route.

All other Pavlovich buses in the city were stopped and drivers asked to check fuel systems were secure.

"We began an audit of our buses at 9am this morning, which will be completed this evening, to ensure that hose clamps are secure to minimise the risk of further incidents of this nature," Pavlovich said.

"We are sorry for any inconvenience caused to bus passengers and particularly other motorists."

​Hamilton police Senior Sergeant Greg Foster said there are multiple diesel spills on all the main roads in Hamilton - stretching from The Base to Chartwell.

It appeared the city bus spilled diesel as it went around corners, he said.

The bus ran out of fuel at Chartwell, where the driver requested help.

Police were at the worst affected spills and roading contractors worked to clear them up, Foster said.

Spills occurred at Tasman Rd; Avalon Dr; Ellicott Rd; Whatawhata Rd; Killarney Rd; Ohaupo Rd; Pembroke St; Anzac Dr; Hamilton East; Clyde St; Knighton Rd; Old Farm Rd; Peachgrove Rd.

The worst affected areas were at Mangaharakeke Dr, Avalon Dr and SH1 and Whatawhata Rd at Newstead.