SF leader 'mired in IRA murder machine'
Speaking in Temple Bar, Dublin, as he handed in his papers to officially become an MEP candidate, Mr Hayes said Mr Adams and Sinn Fein must address Mr Rogers' allegations.
"Mr Adams needs to tell the truth on this, but the problem is would anyone believe him if he said it?" asked Mr Hayes.
Earlier, Sinn Fein deputy leader Mary Lou McDonald dismissed the bombing allegations as "nothing new".
"That is a recurring theme in media circles and becomes more attractive around election times.
"Any questions you have around Gerry are more appropriate to direct them to appropriate people," she said.