"We are changing president but sadly the questions remain the same for us," Pierre-Yves Schneider, the spokesman for the Friends of Ghislaine Dupont and Claude Verlon group told RFI.
In an open letter to Macron, they said that incumbent François Hollande had "recognised that the authors of the crime of Kidal were in fact armed groups implicated in different hostage-takings in north Mali".
Dupont and Verlon were taken captive in the Malian city shortly after it was recaptured from armed Islamists then taken out into the countryside where they were shot dead.
A French TV documentary in January claimed that some of ransom for a group of four hostages held in Niger was never paid to the kidnappers and that the RFI reporters were murdered as a reprisal.
Hollande said that the allegation had not been proved, according to the open letter.
A negotiator from Niger has denied that any of the ransom vanished and said there was no connection between the cases.
Schneider insisted that some money had disappeared and called on Macron to declassify a number of military documents relating to the case that are currently being kept secret.
Press freedom campaign Reporters Without Borders backed the call on Friday.
The investigations into the killings of photojournalist Camille Lepage in the Central African Republic in 2014 and Guy-André Kieffer in Côte d'Ivoire in 2004 should also be speeded up it said in a statement on the third anniversary of Lepage's death.