DUBLIN—The move by Allergan plc (NYSE: AGN) to transfer patents for the dry eye treatment Restasis to New York’s Saint Regis Mohawk Tribe is going to be investigated by the House’s Committee on Oversight and Government Reform.

Four U.S. senators previously said they wanted to pursue an investigation of the unusual arrangement, as VMail reported.

In a letter earlier this week to Allergan, the Oversight Committee said it found the patent deal to be “unconventional maneuver” and asked Allergan to cooperate with the review by disclosing all documents related to the agreement to the committee, according to various news reports. The letter also stated that Allergan’s novel deal could “impair competition across the pharmaceutical industry.”

Allergan has said it plans to cooperate with the House committee’s requests.

In September, Allergan announced that the Saint Regis Mohawk Tribe had taken ownership of all Orange Book-listed patents for Restasis, and that Allergan had been granted exclusive licenses in the patents related to the product. The tribe subsequently sought a dismissal of ongoing inter partes review (IPR) of the Restasis patents based on their sovereign immunity from IPR challenges, according to Allergan’s announcement at the time.

Allergan previously defended its deal with the St. Regis Mohawk Tribe and has asked Congress instead to review the current IPR process that impacts the timeline for approving generic drugs. Allergan’s chief legal officer, Bob Bailey, described the company’s patent transfer as a “sophisticated opportunity to strengthen the defense of our Restasis intellectual property in the upcoming IPR proceedings before the U.S. Patent Trial and Appeal Board.” He also noted that Allergan evaluated this unique approach “with expert counsel in patent and sovereign immunity law” before making this move.