Freemasons in the police force are blocking reform and obstructing the promotion of female officers and personnel from black and ethnic minorities, the outgoing chairman of the Police Federation has said.
Steve White claimed his colleagues had suspicions that members of the secretive brotherhood had stood in the way of reforms to the force in England and Wales.
"What people do in their private lives is a matter for them. When it becomes an issue is when it affects their work," he said.
"We need to make sure that people are making decisions for the right reasons and there is a need for continuing cultural reform in the Fed, which should reflect the makeup of policing."
White claimed that powerful figures within the Police Federation, which represents 120,000 officers nationwide, were masons. He told The Guardian that in some branches of the organisation "a significant number of representatives are Freemasons".
He expressed concern that attempts to promote women into senior positions across the force might be scuppered by the influence of the group.
"The culture is something that can either discourage or encourage people from the ethnic minorities or women from being part of the organisation," he added.
The masons responded that there was no conflict of interest for police officers belonging to the fraternity, which is the subject of much speculation and myth-making.
Mike Baker, spokesman for the United Grand Lodge, said: "We are parallel organisations, we fit into these organisations and have high moral principles and values."
New rules within the Police Federation have been implemented to end the dominance of white male officers in senior roles. White said the federation had been transformed under his stewardship from being seen as an irrelevance to becoming "the trusted voice of the front line and the service".
He claimed the new promotion regulations would make it less easy for Freemasons to favour each another over other job applicants.
White said: "It's about trust and confidence. There are people who feel that being a Freemason and a police officer is not necessarily a good idea. I find it odd that there are pockets of the organisation where a significant number of representatives are Freemasons."
"The new regulations will mean Freemasons leading to an old boys' network will be much less likely in the future."