Barclays chief executive Jes Staley is entering a crucial period that will determine his future amid a spate of departures from the banking giant’s compliance division and growing questions about its culture.

The bank is without a permanent compliance chief following three departures in recent months. It also lost its information security head in November.

The moves come as the 61-year-old American waits to hear if UK and US regulators will take action against him in the coming months for trying to identify the author of an anonymous whistleblowing letter. Staley has said he would “cooperate fully” with any investigation.

Paul Moore, who in 2004 blew the whistle on Halifax Bank of Scotland following a stint as the head of its group regulatory risk arm, said the timing of the departures raised red flags.

He said the timings could indicate those leaving were being “blamed and scapegoated for the failures of the executive and removed and gagged”. He added they could also have “left of their own accord because they lost trust in the organisation” and that either case would “not reflect well on Barclays”.

Nick Bayley, a managing director in the compliance and regulatory consulting practice at Duff & Phelps, who used to work in the Financial Conduct Authority’s enforcement division, said: “When several senior compliance people leave an organisation in close succession it can be a flag for regulators and is something they might want to look into.

“When some smaller firms have had numerous compliance departures it has sometimes been indicative of underlying cultural problems.”

Barclays’ group head of compliance Michael Roemer left in October to join US lender Wells Fargo. The bank’s global head of whistleblowing Jonathan Cox left around the same time, reportedly after reaching a settlement with Barclays and withdrawing an employment tribunal case.

Troels Oerting also left his role as group chief information security officer. He is reported to have been the one asked by Staley to identify the whistleblower.

Earlier this year the chief compliance officer for Barclays International, Francois Jourdain, stepped down from his role to focus on chairing an industry working group. A bank spokesman said at the time that he remained an employee of the bank and that the move would give him “greater flexibility to spend more time with his family”.

Barclays has yet to announce permanent replacements for Roemer, Cox or Oerting.

Laura Padovani has taken over as interim group chief compliance officer, Richard Atterbury is interim head of whistleblowing, and the bank’s cyber security operations head Paul Gillen was reported to have taken on Oerting’s remit on an interim basis.

One person close to the situation said Roemer had left for a job that allowed him to move to the US and that the departures of Oerting, Cox and Jourdain were unrelated to whistleblowing.

A former compliance professional at the bank, who left before the recent departures, said he had found it “a difficult place to work” due to what he called a “very political” culture and the way the compliance team was regarded internally.

An internal investigation found Staley broke the bank’s whistle-blowing policy. The FCA is due to reveal its decision in the spring.

One compliance expert said that Barclays may have endured a lot of departures because its compliance team is so large. One headhunter added: “When I speak to senior people, there aren’t many that wouldn’t be open to looking around for other options.”

Barclays and the regulators declined to comment.