A councillor has accused the company behind HS2 of "deliberate misinformation" after a Freedom of Information request showed it does not know the current cost of the project.

The estimated £50billion cost of the scheme is based on 2011 prices, when the route of HS2 was confirmed as cutting through the Chilterns Area of Outstanding Natural Beauty.

Chiltern District Council's Seb Berry submitted an FOI request asking HS2 Ltd and the Department for Transport for an estimate on the current cost of HS2 based on 2015 prices.

Cllr Berry was stunned to receive a response from HS2 Ltd saying: "We do not hold this information" - with a follow-up request for information stating there was "no business need to estimate the cost of HS2 in 2015 prices".

HS2 Ltd said this is standard procedure for major infrastructure projects.

But Cllr Berry, who was elected onto the council on an anti HS2 ticket, said: "It beggars belief that ministers don't know what the current price tag of HS2 is. Surely the DfT must know the answer to this most basic of questions?

"In their own PR terms it's obviously better for government and HS2 Ltd to keep using the lower 2011 prices figure, a fact rarely, if ever, explained in media coverage of the scheme.

"With each passing year however, the government's failure to confirm the cost in current prices begins to look like deliberate misinformation rather than convenient spin."

HS2 Ltd spokesman Katherine Button said: "Using a consistent price base for costs provides the Department for Transport with transparency around how costs and benefits have changed over time. This is no different from the manner in which the Department has supported the delivery of other major infrastructure programmes."