WASHINGTON — The former top lawyer for Turing Pharmaceuticals said Thursday that he and other executives warned Martin Shkreli against the drastic price hike that triggered a national backlash against the company and its then-32-year-old CEO.

The Senate Committee on Aging subpoenaed current and former Turing executives to appear Thursday and explain the fiftyfold price hike of Daraprim, a drug used to treat a life-threatening parasitic infection.

“Mr. Shkreli told me that he was the most knowledgeable person with regard to this business model,” said Turing’s former general counsel, Howard Dorfman. “That I was seriously misinformed — despite my 30 years in the industry.” Dorfman said he was fired in August, shortly after raising his concerns.

Last month House lawmakers subpoenaed Shkreli to appear at a similar hearing, though he declined to answer questions, citing his Fifth Amendment right.

Shkreli resigned in December.

“What improvements did Turing make to Daraprim to justify raising the price from $13.50 per pill to $750 per pill?” asked Sen. Susan Collins, R-Maine, who chairs the committee.

Interim CEO Ronald Tilles acknowledged that the currently sold pill is the same drug that has been available since the 1950s. It sells overseas for about $2.

After coming under fire last fall, Turing said that it was investing its profits into a “next generation” treatment that would be superior to Daraprim. But Dorfman said that there was no such research plan in place at the time of the price increase.

“The price increase, as contemplated and subsequently announced, was not justified by any such actual expenditure,” he testified.