PC Ian Terry: Shot officer's family condemns joke photo
His family said the photo was taken around the time of the inquest and showed lessons had not been learned.
GMP said it had removed three officers from its firearms unit.
The photo was found on a computer at a police officer's home during an unrelated raid.
It shows one officer pointing a shotgun at the other who is jokingly posing on the bonnet of an armoured vehicle.
"These images are clearly distressing to the family and highlights that GMP, and in particular the tactical fire arms unit, haven't learnt anything from the circumstances surround the tragic death of Ian Terry," said James Reilly, of Ralli solicitors, who are representing PC Terry's family.
A statement issued by his family added: "The family understand from GMP that the photograph was taken 18 months to two years after Ian's death, which would be at the same time as the inquest was being heard (March 2010).
'Family's distress' "Ian's family are extremely distressed at the sight of the image released today. They feel that, following the death of a fine young officer, other officers feel it somehow appropriate to fool around during training exercises."
Deputy Chief Constable Ian Hopkins said: "Greater Manchester Police expects the highest professional standards from all officers and staff and clearly this falls well short.
"This matter was dealt with quickly as soon as it came to light in June 2011 and the three officers involved were removed from the firearms unit.
"Their conduct let themselves, their colleagues and the rest of the force down."
Pc Terry, from Burnley, Lancashire, was shot dead by a colleague at a warehouse in Manchester during an exercise in which he was playing the role of a criminal fleeing in a car.
His friend told an inquest that he acted instinctively.
Following PC Terry's death, the Health and Safety Executive said it would prosecute the force and two of its officers.
However, the Crown Prosecution Service ruled there was insufficient evidence to bring criminal charges against the officer who shot Pc Terry or GMP.