Wiltshire Police is to be probed after allegations made by a retired senior officer were referred to the Independent Police Complaints Commission (IPCC).
An IPCC spokesman said it is to investigate "allegations concerning Wiltshire Police's handling of an alleged claim of child sexual abuse made in the 1990s".
He added: "It is alleged that a criminal prosecution was not pursued, when a person threatened to expose that Sir Edward Heath may have been involved in offences concerning children.
"In addition to this allegation, the IPCC will examine whether Wiltshire Police subsequently took any steps to investigate these claims."
Sir Edward was the editor of the Church Times between 1948 and 1949 before his election as Member of Parliament for Old Bexley and Sidcup in 1950.
A spokesman for Wiltshire Police said: "Following the announcement today regarding an independent investigation by the IPCC into allegations concerning how Wiltshire Police handled an alleged claim of child sex abuse made in the 1990's, we are carrying out enquiries to identify if there are any witnesses or victims who support the allegations of child sex abuse.
"On becoming aware of the information, Wiltshire Police informed the IPCC and later made a mandatory referral. The IPCC investigation will specifically consider how the force responded to allegations when they were received in the 1990's."
"Sir Edward Heath has been named in relation to offences concerning children. He lived in Salisbury for many years and we would like to hear from anyone who has any relevant information that may assist us in our enquiries or anyone who believes they may have been a victim.
"We are working closely with the NSPCC to ensure that any victims are appropriately supported. They provide trained helpline counsellors to listen and provide assistance.
"We take all reports of child abuse, either current or that occurred in the past very seriously. Victims will receive support throughout any investigation and associated judicial process.
"If there is evidence of offences having been committed we will ensure that , if possible, those responsible are held to account through a thorough and detailed investigation. This includes any other parties who are identified as having been involved in child sex abuse.
"Some people may never have spoken out about the abuse they have suffered but we would urge them to please contact us and to not suffer in silence."
NSPCC chief executive Peter Wanless said: "It's important that people who believe they have been victims of abuse have the confidence to speak out knowing that their voices will be listened to.
"Whether abuse happened in the past, or is occurring today, whether those being accused are authority figures or not, allegations of crimes against children must be investigated thoroughly.
"While some people wait years before speaking out we would urge them to act quickly so they can get help as soon as possible. Our trained helpline counsellors are always on duty round the clock to listen and provide assistance."