Barclays chief executive Jes Staley has been fined £642,430 ($871,000) by UK regulators for trying to identify an anonymous whistleblower who made allegations about Staley’s role in recruiting another employee, reports FCPA blog.

The Financial Conduct Authority and the Prudential Regulation Authority said Staley failed to “act with due skill, care and diligence” by trying to hunt down the whistleblower.

The FCA and PRA started investigating Staley a year ago.

Barclays said it would cut his bonus by £500,000 ($678,000).

An anonymous whistleblower who claimed to be a shareholder sent a letter to Barclays’ board in 2016.

The letter raised concerns about how a senior Barclays employee was recruited and Staley’s role in the hiring.

Staley asked Barclays’ security chief, Troels Oerting, to find out who wrote the letter, which had a U.S. postmark.

Oerting asked U.S. federal law enforcement authorities for help tracking down the sender.

On Friday, the Financial Conduct Authority and the Prudential Regulation Authority said Barclays is now subject to “special requirements.”

The bank is required to “report annually to the regulators detailing how it handles whistleblowing, with personal attestations required from those senior managers responsible for the relevant systems and controls.”

The investigation found that Staley “made no personal gain” but committed “serious errors of judgment.”

Staley had a conflict of interest with the whistleblower’s letter, the regulators said. He “needed to take particular care to maintain an appropriate distance from” the bank’s investigation.

“There was a risk he would not be able to exercise impartial judgment in relation to how Barclays should respond,” the agencies said.

The regulators said they fined Staley about 10 percent of his total compensation.

He earned £2.35 million ($3.19 million) in 2016 and received a bonus of £1.3 million ($1.76 million).

The agencies could have fined him about £918,000 ($1.25 million). They discounted the fine by 30 percent because he settled at an early stage.

In a statement to the BBC, Staley, 62, said his personal involvement was inappropriate. “I have apologized for mistakes which I made,” he said.”

“I accept the conclusions of the board, the FCA, and the PRA, following their respective investigations, and the sanctions which they have each applied,” Staley said.