The state House of Representatives announced Tuesday it will investigate Rep. David Cook, R-Globe, following two complaints.

The complaints come as questions of potential conflicts of interest swirl around Cook's relationship with a lobbyist for the agricultural industry, who was suspended by her employer as they investigate claims of "professional misconduct."

House Ethics Committee Chairman T.J. Shope, R-Coolidge, did not elaborate on details of the complaints or identify the complainants. He said late Tuesday that the committee's rules require its members review that information before it is released to the public. And Shope, who represents the same legislative district as Cook, temporarily recused himself from all committee business.

Still, the complaints mark a turn in a drama that has played out in the background of the first weeks of this year's legislative session.

An anonymous tipster sent The Arizona Republic and other news organizations a stack of intimate and personal letters last month that Cook allegedly wrote to the lobbyist, AnnaMarie Knorr.

The two maintained in separate interviews that they are friends and do not have a romantic relationship.

But the letters raised questions about the nature of the relationship between Cook and Knorr, who represents the Western Growers Association, a trade association for produce farmers.

That has led to concerns about a conflict of interest because Cook sits on committees central to the industry Knorr represents, and he has sponsored bills that the association has supported.

Knorr told The Republic that the letters were shared with newspapers as part of a smear campaign launched by her father and husband to convince her to stay in her marriage. Knorr is the daughter of Bas Aja, a power broker at the Capitol who for decades has lobbied on behalf of the Arizona Cattle Feeders’ Association.

In an email obtained by The Republic, Aja told the chief of staff for the House that he confronted Cook last year about his "about his drinking/drunkenness." Aja said the lawmaker called him late at night while intoxicated and sent him threatening emails on multiple occasions.

Cook did not immediately respond to a message seeking comment.

It is unclear when the Ethics Committee might take up the complaints. House Speaker Rusty Bowers, R-Mesa, tapped Rep. John Allen, R-Scottsdale, to chair the committee while Shope has recused himself.

Contact Andrew Oxford at andrew.oxford@arizonarepublic.com or on Twitter at @andrewboxford.