Four suspects are understood to have been identified by police investigating possible criminal charges over the Post Office scandal.

Perjury and perverting the course of justice are thought to be among offences being considered.

Hundreds of sub-postmasters were wrongly prosecuted for stealing from branches after faulty Horizon software caused accounting errors.

West Byfleet subpostmistress Seema Misra was sent to jail in 2010 when she was 8 weeks pregnant and gave birth while on a tag.