The files emerged more than a month ago and are thought to be connected to allegations of a Westminster-based paedophile ring.
Pete Saunders, CEO, National Association of People Abused in Childhood (NAPAC), a Christian, believes the files are being kept secret ahead of May's poll, because he thinks the potentially explosive revelations could cost all the parties votes.
Speaking to Premier, Mr Saunders said: "My gut feeling has to be that in the run up to a general election, which we're got in a matter of weeks, all the political parties at the moment; I suspect will be running a little bit scared because I don't think any of them would want any of their skeletons if you like aired in public, and I think that is what is in prospect at the moment."
At the start of February Cabinet Office minister Francis Maude said: "Officials have identified four additional relevant files, one of which was marked for destruction."
The delay has angered the family of Martin Allen who was 15 years old when he vanished in London nearly 35 years ago.
The teenager was last seen on the London Underground with an unidentified man at Gloucester Road station on 5 November 1979.
His brother Kevin Allen told Sky News he was "pretty definite" there is a link between the establishment abuse networks in Westminster and his brother's disappearance.
He said he could not accept that the names of the files are still being withheld.
Pete Saunders, CEO, National Association of People Abused in Childhood (NAPAC):