RFU disciplinary officer Jeff Blackett heads a five-man panel.
"The committee also heard evidence and submissions from the EPCR disciplinary officer, Liam McTiernan.
The case will be heard by the RFU's disciplinary officer, the high court judge Jeff Blackett.
The RFU's chief disciplinary officer, Jeff Blackett, was on Monday flying back from Auckland where he had been attending a pre-World Cup disciplinary meeting.
The Rugby Football Union's chief disciplinary officer, Judge Jeff Blackett, yesterday concluded his investigation into events after England's first-Test defeat in Auckland.
Northampton suspended Clark, a former England Under-20 captain, immediately the citing was announced and the case was heard by the RFU's disciplinary officer, High Court judge Jeff Blackett.
The Lions leave for Hong Kong on Monday but Hartley's participation will depend on Sunday's hearing chaired by Jeff Blackett, the Rugby Football Union's chief disciplinary officer.
In all cases, a citing commissioner will later view the video footage and decide if further action needs to be taken, such as an off-field yellow card or an appearance before a disciplinary officer.
Judge Jeff Blackett, the union's disciplinary officer, said: "If ERC finish the process and decide they have taken it far enough, and decide it comes back to the RFU, these things will take a certain time".
The RFU's disciplinary officer, Jeff Blackett, will announce in the coming days the composition of a panel that is set to examine allegations of a cover-up involving Quins' most senior executives.
