Police chiefs have reportedly produced a 93-page guide telling officers how to ride a bicycle.

The Police Cycle Training Doctrine, which comes in two volumes, gives officers advice on how to balance so they do not fall off, how to brake and how to avoid obstacles such as kerbs and rocks.

But the Association of Chief Police Officers (ACPO), which produced the guide, said the guidance had not yet been fully approved.

The guide, seen by The Sun newspaper, warns officers not to tackle suspects while they are still "engaged with the cycle", includes a diagram on "deployment into a junction", and suggests they wear padded shorts for "in-saddle comfort".

The guidance also notes that undercover officers may have to ride without a safety helmet, but warns: "This lack of protection must be noted and a full risk assessment of the required role to be undertaken."

An ACPO spokeswoman told the newspaper "This guidance may have been drawn up by ACPO but we haven't fully approved it yet."

Taxpayers' Alliance campaign director Mark Wallace added: "This is an absurd waste of police time and thousands of pounds of taxpayers' money."