The Metropolitan Police should make its collection of crime artefacts publicly available in order to generate income for frontline policing, according to a new report.

The History's Life Sentence report, written by Roger Evans, a member of the Greater London Authority’s policing and crime committee, calls for the collection be transformed into a visitor attraction rather than remain hidden away and “left to fade into disrepair”.

The collection is housed in New Scotland Yard and is accessible by invitation-only.

Notable items include the From Hell letter allegedly written by Jack the Ripper, evidence that led to the prosecution of Ronnie Biggs and his fellow Great Train Robbers and a collection of hangman's nooses and death masks from a number of capital punishment executions including the last woman executed, Ruth Ellis.

In his report, Evans ruled out opening a dedicated crime museum. He states that substantial running costs and pressure on the Met’s budget would make it “highly unlikely that the museum could operate at anything but a loss”.

Instead, he recommended that the Met exhibits its collection on a temporary basis in an existing museum, independently or through a private partner.

“Given the broad appeal of both the crime museum’s collection and the draw of viewing exhibits previously locked away from the public eye, it could realistically lead to visitor numbers around 300,000 over a three-month exhibition,” the report states.

“If entrance was charged at £15 a ticket, the exhibition could look to bring in up to £4.5m. Even if the Met were able to receive just a fifth of this turnover, it would pay for 54,900 additional frontline police hours.”

The nature of the collection could mean restrictions on what such an exhibition could display, with items relating to crimes committed within the past 50 years potentially omitted.

The Met, which will move from New Scotland Yard to Whitehall in 2015, said it had no plans to proceed with the recommendations.  

The Mayor’s Office in London has previously proposed opening a Blue Light Museum for all the emergency services but this was put on hold because of the economic climate.