The Crown Prosecution Service will be considering whether to charge anyone over the ‘cash for honours’ scandal after detectives completed their probe.
The Metropolitan Police said a 216-page document was given to prosecutors with supporting material.
The scandal involves claims that peerage nominations were exchanged for sizeable contributions to leading political parties.
Scotland Yard’s findings will play a crucial part in deciding who – if anyone – will be charged over the alleged sales.
The Met said in a statement: “It is now a matter for the CPS to consider the evidence, advise us on whether any further inquiries are necessary and whether any charges should be brought.”
If prosecutors believe there is sufficient evidence, charges will be laid for breaches of the 1925 Honours Act, which remains the ‘main focus’ of the probe, rather than claims of a cover-up.
Altogether 136 people – including Prime Minister Tony Blair – have been questioned in the course of the investigation, either as witnesses or suspects, and 6,300 documents passed to prosecutors.
Three people remain on police bail – Mr Blair’s chief fundraiser Lord Levy, No 10 aide Ruth Turner, and wealthy Labour Party backer Sir Christopher Evans.