Sydney developer Joseph Alha, who described Daryl Maguire as his "mentor", has told a corruption hearing that he communicated with the former MP via an encrypted smartphone app and then deleted the messages.
Mr Alha told the Independent Commission Against Corruption (ICAC) last week he helped Mr Maguire identify "anti-development" people who were applying for newly-formed planning panels.
Mr Alha reappeared on Thursday and agreed with counsel assisting ICAC Scott Robertson that he communicated with Mr Maguire via WhatsApp because he knew it "to be end-to-end encrypted and harder to be intercepted and listened in to".
"The particular messages ... are they still available to you on an existing telephone?" Mr Robertson asked.
"No they aren't ... because I deleted them," Mr Alha replied, stating that they were "personal" messages.
Mr Alha agreed that one reason he deleted his messages was that he knew an ICAC inquiry would begin or was likely.
Mr Alha denied deleting the messages because they implicated himself, telling the hearing that Mr Maguire told him ICAC was "crazy" and "you twist things, you turn things".
ICAC then seized Mr Alha's iPhone, PIN and Apple account password.
Mr Alha said he kept taking phone calls from Mr Maguire as the former MP was "in a very dark place and I think he still is".
ICAC heard from Robert Vellar on Friday, who used to work as chief of staff to then-NSW Planning Minister Anthony Roberts.
Mr Vellar said he felt "ambushed" when Mr Maguire invited him to a meeting in Parliament House and found Mr Alha in attendance, who had "a whinge about planning in relation to a site" in suburban Sydney.
Mr Vellar denied a suggestion from Mr Maguire's solicitor that he had expected Mr Alha to be there but admitted he did not make a written record afterwards.