Bank of England Governor Mark Carney said he does not know when British interest rates should start to rise but are likely to remain low "for some time".

Mr Carney told the Treasury select committee he expects borrowing costs to rise eventually, saying the economy would increasingly require a higher level of neutral rates as it recovered from the financial crisis.

He said: "Eeven with limited and gradual rate increases it still will be a relatively low interest rate environment.

"The question in my mind is when is the appropriate time for interest rates to increase, and that is strongly consistent with the strength of the domestic economy."

The BoE surprised many investors earlier this month when it showed no sign that it was gearing up for an increase in interest rates, saying Britain's near-zero inflation would pick up only slowly even if rates stay on hold throughout next year.

Mr Carney said then that the Bank would raise rates when the time was right.

The deepening slowdown in the global economy has kept many BoE rate-setters on the fence.