Goldman Sachs Group Inc. executive Andrea Vella told a London court that former colleagues who criticized the bank, including the author of a book alleging it mistreated clients, were being dishonest because they wanted to make money.

Testifying in a $1 billion trial between Goldman Sachs and Libya’s sovereign wealth fund, Vella dismissed comments from two former employees that cast the bank in a negative light. Vella, co-head of Asia investment banking, was shown a chapter of Greg Smith’s book “Why I Left Goldman Sachs” about hunting elephants, a reference to the relentless pursuit of very large trades.

“He may have compromised his honesty for writing or selling a book,” Vella said, explaining that he disagreed with Smith’s account.

The $60 billion fund, the Libyan Investment Authority, set up under former ruler Moammar Qaddafi to manage the African nation’s oil wealth, is suing Goldman Sachs and, in a separate suit, Societe Generale SA, to recover losses from investment deals dating back to the market collapse of 2008.

Smith’s “book was about as accurate as it was popular,” a Goldman Sachs spokesman said in a statement. A spokesman for the LIA’s lawyers didn’t immediately respond to an e-mail seeking comment.

Vella was also shown a 2011 letter written to Goldman Sachs by lawyers for a former banker, Mohamed Bani, in which he raised concerns about the LIA deals. Vella said that it made him doubt Bani’s honesty.

‘Looking for Money’

“He was looking for money from Goldman Sachs,” Vella told the court. Both Bani and Smith “are writing things that are inaccurate,” he said. “They have an agenda.” Bani was told in 2011 not to return to his job in the emerging markets structuring team.

Several LIA officials have testified in the trial that they didn’t fully understand the derivatives sold by Goldman Sachs. One said he had never heard of the New York bank before meeting its employees. Goldman Sachs argues that the LIA knew enough to appreciate the risks of investing and the fund’s executives were angry because they lost money, not because of mistreatment.

Bani’s lawyer at Withers didn’t immediately respond to an e-mail seeking comment. The publisher of Smith’s book didn’t immediately respond to an e-mail seeking comment outside of normal working hours, and a phone number he used was no longer connected.