LABOUR binned papers that would have shown the address where “two homes” Angela Rayner claimed to live in 2014.
The party said it has “disposed of” the application she filed then to become a parliamentary candidate for the party in 2015.
A spokesman yesterday said it was erased some time ago in line with data protection laws.
It would have revealed where the now deputy leader had claimed to be living and been important to the ongoing police probe.
Greater Manchester Police are looking into accusations Rayner broke electoral law by providing a false address to authorities.
Separate tax issues may also be under investigation but the force is not disclosing details.
Ms Rayner has maintained that during the 2010s she lived at her former council house in Vicarage Road, Stockport.
Neighbours say she was rarely there.
Photographs and social media posts show that she was, instead, frequently at her then husband Mark’s address at nearby Lowndes Road.
Ms Rayner has denied wrongdoing but has refused to publish legal advice from the period which she claims exonerates her.
Journalists had been asking Labour to see her selection papers while trying to become Labour’s candidate for Ashton-under-Lyne at the 2015 election.
It initially refused, but last night confirmed: “The document is no longer held and had been disposed of, in line with legal data protection requirements.”
Ms Rayner has promised to resign if found to have broken the law.
Giving a false address on the electoral roll is an offence under the Representation of the People Act 1983.