The NDC chairman had earlier refused to honour an invitation from the Criminal Investigation Department (CID) over the matter, after the department said a suspect had mentioned his name.
The Council of Elders of the NDC organised a press conference and backed his decision not to honour the invitation. The elders subsequently urged ex-appointees of the erstwhile Mahama administration not to cooperate with the CID.
In February, Ampofo came in for strong criticism after an audio in which he was allegedly inciting violence leaked.
The NDC Chairman is heard on the tape planning to use a series of politically motivated kidnappings ahead of polls planned for 2020.
He's also heard urging the party's communicators to target the Chairperson of the Electoral Commission, Jean Mensa.
And sanctioning attacks and insults on the Chairman of the National Peace Council, Rev. Emmanuel Asante.