Lawrence Culp has held the top job at General Electric for nearly one year and on Thursday one of the industrial conglomerate's biggest shareholders, activist investor Nelson Peltz, gave him a shout-out for being "fantastic."

"Larry Culp is a star," said Peltz who runs $9-billion hedge fund Trian Partners, adding "he knows how to run a business. He is fantastic."

Peltz was speaking at the CNBC Institutional Investor Delivering Alpha conference in New York roughly four weeks after forensic accountant Harry Markopolos issued a report in August alleging that GE is concealing deep financial problems.

Culp said Markopolos’ 175-page report contained factual errors and constituted “market manipulation - pure and simple,” because Markopolos stood to profit from short-selling tied to its release.

Culp, named to the GE board in early 2018, was elevated to CEO that October when the board ousted John Flannery. Peltz said on Thursday that his work on the board gave him a better sense of what was happening at the company so that he was more prepared for the problems awaiting him.

Trian has held a seat on the GE board since 2017.