Without a special application to the Home Secretary, the men would continue to receive pension payments while in jail.
Former constable Ronald Palumbo, who was based at Stoke Newington in east London, is serving 10 years for smuggling cannabis worth pounds 2minto Britain. John Donald, a former detective constable with the South East Regional Crime Squad, was taped by the BBC's Panorama programme trying to sell evidence to criminals. He is serving 11 years.
Yesterday a Scotland Yard spokesman confirmed that the Metropolitan Police Commissioner, Sir Paul Condon, had asked the Home Secretary to stop a portion of their pensions. "We have applied to the Home Office to have part of their pensions forfeited," the spokesman said.
The power to cut the pensions applies only in exceptional circumstances, where an officer's behaviour is so bad "it could lead to a loss of confidence in the service as a whole", the spokesman said.
A Home Office spokeswoman said the men could lose up to three-quarters of their pensions - the portion paid for by the taxpayer.
The Police Federation, which represents rank and file officers, backed the move and said it should be done in more cases. Its chairman, Fred Broughton, said: "Evidence suggests that at present chief officers have not been applying these rules."