A member of an alleged $144 million tax fraud syndicate who allegedly extorted the group flew into a rage, saying that Adam Cranston had "taken the f---ing cake for three f---ing years, eaten it [and] spat it in everyone's faces".

But new court documents reveal the syndicate agreed to pay the extortion money in return for a deed of agreement that was carefully designed to make the "straw" directors take the fall and allow the syndicate to continue their fraud.

Tax lawyer Dev Menon appears extensively in the transcripts of telephone taps and listening devices detailed in AFP court affidavits.

"This is stitching up the directors, this is completely stitching them up," tax lawyer and syndicate member Dev Menon allegedly said in an intercepted phone call.

Nine people, including the son and daughter of former Australian Taxation Office deputy commissioner Michael Cranston, have been charged over the scheme that allegedly skimmed PAYG proceeds using a web of payroll companies run by "straw" directors.