Former Conservative prime minister Sir Edward Heath would be questioned over allegations that he raped and indecently assaulted boys as young as 10 were he alive today, a controversial police report has said.

A Wiltshire Police investigation, called Operation Conifer, concluded that seven of the claims would have been sufficiently credible to justify questioning Sir Edward, who was prime minister between 1970 and 1974, under caution.

The report does not address the question of Sir Edward's guilt or innocence because the remit of the two-year £1.5 million inquiry was to see whether there was enough evidence to interview the former MP for Bexley, who died at home in Salisbury in July 2005, aged 89.

None of the allegations about which Wiltshire Police would have questioned Sir Edward relate to when he was prime minister, the force said.

The Crown Prosecution Service has a policy of not making a charging decision on a suspect who is dead because they cannot be prosecuted.

The allegations Sir Edward would have been questioned over include rape of a boy aged 11, indecent assault of a 10-year-old boy and the indecent assault of a 15-year-old boy during three "paid sexual encounters", and are said to have occurred between 1961 and 1992 in the Met Police, Kent, Sussex, the Channel Islands and Wiltshire force areas.

Lord Hunt of Wirral, chairman of the Sir Edward Heath Charitable Foundation, and Lord Armstrong of Ilminster, former Cabinet Secretary, said in a statement: "The Wiltshire Police report is profoundly unsatisfactory because it neither justifies nor dispels the cloud of suspicion."