The former head of the British army has called on the government to pay compensation to African veterans of the second world war who were paid three times less than their white counterparts.

General Lord Dannatt described the discriminatory policy, revealed by the Guardian and al-Jazeera, as “hugely inequitable and wrong”. He urged the defence secretary, Gavin Williamson, to meet surviving ex-servicemen in Africa and issue a retrospective apology.

“It would be perfectly reasonable to ask the government to acknowledge it and, if they felt inclined, to make an apology,” Dannatt told the Guardian. “It is absolutely right to recognise the service of anyone of any colour and indeed nationality that was fighting for the crown in the cause of freedom in the second world war … If there have been abuses relating to their service, then it is absolutely right that they are identified and corrected where possible.”

A “modest ex gratia payment”, he said, would add “substance to the otherwise rather empty words” of an apology.

Dannatt’s intervention came after a documentary film on al-Jazeera English showed that soldiers drawn from Britain’s east African colonies were paid an end-of-war bonus that was graded according to their rank, length of service and ethnicity. The reward for white soldiers – even those from settler communities in the same African colonies – was around three times greater than that given to black troops. Some Africans were forcibly conscripted while others faced an illegal regime of beatings and public floggings.

“That policy seems hugely inequitable and wrong,” added Dannatt, who led the army from 2006 to 2009. “We wouldn’t do that today, you would never get away with it today. It would be outrageous today.”

The revelations of systematic discrimination have already prompted three shadow secretaries of state to demand that their opposite numbers in government launch an inquiry, make a formal apology and pay compensation. Last week, Labour’s Fabian Hamilton, the shadow minister for peace and disarmament as well as foreign and Commonwealth affairs, raised the matter in parliament, backing calls for redress and challenging defence minister Tobias Ellwood to commit to launching “a full and comprehensive Ministry of Defence investigation”.

Ellwood agreed that the issue was “very important” and “something that the secretary of state is also aware of” but incorrectly stated that the Foreign Office was leading on the matter. Foreign Office officials had already confirmed that the Ministry of Defence was taking charge.

The Conservative MP – a former captain of the Royal Green Jackets who is now responsible for veterans’ issues and equality in the armed forces – refused to give any more information about possible plans to make amends.

Dannatt said that the MoD had to take responsibility for a policy formulated partly by its predecessor, the War Office. “They are the heirs and the successors of the War Office, of course they are,” he said.

“I can’t really see why they should be frightened … It’s not going to hurt them politically, it’s not going to hurt the defence budget unduly. It would be seen to be the right thing to do. I would have thought, if I was Gavin Williamson or Tobias Ellwood, the veterans minister, that there is political advantage in doing that. So why not?”

Dannatt, who is also president of the military charity Help for Heroes, said the payment of reparations should coincide with a meeting between Williamson and elderly African veterans, adding: “That would be a very helpful thing to do.” Tracking down African veterans eligible for this compensation must be swift, he said, as their advanced age meant “most of them will be dead” if the matter is delayed.

The MoD did not respond to requests for comment.