A new report claims that John Lyttle, former CEO of Boohoo, a British fast-fashion retailer worth £500 million, was allegedly being stalked in the lead-up to his exit in October. 

He led the fast-fashion group for five years through financial troubles, a battle with its majority shareholder, and claims of poor working conditions that shook investor confidence. The company’s sales have plunged recently as it faces stiff competition from cheaper online shopping rivals like Shein. 

Other executives at Boohoo, which owns Debenhams and PrettyLittleThing, also reportedly faced stalking and “corporate espionage,” The Times reported on Thursday. That involved being followed by people on public transport or in other public places across the U.K., such as in London, Kent, and Manchester. 

Unregistered surveillance equipment was found at Boohoo’s headquarters in Manchester last month, possibly recording the staff’s movements. The area outside the office reportedly lacks cameras.

The identity of those allegedly stalking Boohoo executives is unknown, as Manchester and Kent police are still investigating the matter. However, the U.K. Information Commissioner’s Office is “aware of concerns regarding the discovery of surveillance equipment outside its head office.” 

Concerns about the stalking of Boohoo’s top bosses sent a wave of fear through other staff members and their families. 

Boohoo declined to comment on its efforts to improve the safety of its top-level executives, including Dan Finley, who took over from Lyttle as CEO. 

“It would be inappropriate to comment whilst a police investigation is ongoing,” a Boohoo Group spokesperson told Fortune. 

Worries around Boohoo executives’ security in the U.K. underscore a problem that’s taken center stage this week: CEO safety. The murder of 50-year-old Thompson in New York brought the issue to the global forefront as UnitedHealth Group is the world’s eighth-largest company by revenue, according to the Fortune Global 500 ranking.

The insurer has had its fair share of battles with customers over coverage denial. Thompson’s tenure as head of UnitedHealthcare, a division of UnitedHealth Group, lasted about three and a half years and was marked by remarkable profits. 

Three days since the shooting, Thompson’s killer is still at large, leaving the motive unknown. 

“If it was motivated by the business that they’re in—the health care business, or anything that could be related—then certainly that’s a wake-up call to a lot of CEOs and executives traveling throughout the country and the world,” Glen Kucera, president of the enhanced protection services division at Allied Universal, a security services company, told Fortune earlier this week.

Although the U.S. and Europe differ in nearly every aspect of business, Lyttle’s example highlights that recognizable C-suite executives face more security threats today. 

Protecting the world’s most high-profile CEOs is a multimillion dollar undertaking: Meta chief Mark Zuckerberg’s personal security costs $23.4 million, while Tesla CEO Elon Musk’s security services cost $2.4 million.   

The concept of dedicated security services for CEOs is still nascent in Europe compared with the U.S. But as corporations find themselves in the midst of global disruptions and wars, awareness of the safety of their top leaders is starting to rise. 

Private security firm Allied Universal, which handles security services for 80% of Fortune 500 companies, has seen a spike in demand for its services, its CEO Steve Jones told the Financial Times. That’s resulted in a labor shortage despite having 17,000 staff, many of whom are former police or military members.

Since the incident with Thompson, the firm’s phone has been “ringing off the hook,” per the New York Times.