LONDON (AP) — Cambridge Analytica’s ex-CEO, Alexander Nix, has refused to testify before the U.K. Parliament’s media committee, citing British authorities’ investigation into his former company’s alleged misuse of data from millions of Facebook accounts in political campaigns.

Nix gave evidence to the committee in February, but was recalled after former Cambridge Analytica staffer Christopher Wylie sparked a global debate over electronic privacy when he alleged the company used data from millions of Facebook accounts to help U.S. President Donald Trump’s 2016 election campaign. Wylie worked on Cambridge Analytica’s “information operations” in 2014 and 2015.

Wylie has also said the official campaign backing Britain’s exit from the European Union had access to the Facebook data.

Former Cambridge Analytica business development director Brittany Kaiser told lawmakers that in an atmosphere where data abuse was rife, she believed the leadership of the Leave.EU campaign combined data from members of the U.K. Independence Party and from the customers of two insurance companies, Eldon Insurance and GoSkippy Insurance.

The two executives were then able to create their own “their own Cambridge Analytica” using her proposals, Kaiser testified.

“Arron Banks and Andy Wigmore have told multiple individuals that they took my proposal and copied it and they created their own Cambridge Analytica, which they called Big Data Dolphins in partnership with the data science department at the University of Mississippi,” Kaiser said.

The university rejected Kaiser’s allegation.

“The assertion that the University of Mississippi has received or analyzed any data from these companies is not true,” Alice Clark, vice chancellor for university relations, said in a statement emailed Tuesday to The Associated Press.

Leave.EU’s communications director, Andy Wigmore, also called Kaiser’s statements a “litany of lies.”

Cambridge Analytica has previously said that none of the Facebook data it acquired from an academic researcher was used in the Trump campaign. The company also says it did no paid or unpaid work on the Brexit campaign. The company did not respond to requests for comment from The Associated Press on Tuesday.