Switzerland’s top prosecutor opened a probe to gather information into potential crimes that may have taken place around UBS Group AG’s takeover of Credit Suisse Group AG, while the emergency combination of the nation’s two biggest banks begins to take shape.

The deal signed last month may reduce the overall workforce by up to 30%, with as many as 11,000 cuts in Switzerland and another 25,000 worldwide, Swiss newspaper SonntagsZeitung reported on Sunday, citing an unidentified senior manager at UBS. Executives at the Swiss bank said last week that they’re looking to provide clarity on job cuts as soon as possible but that it was too early to give firm numbers.

A spokesperson for UBS declined to comment on the report.

Switzerland’s Office of the Attorney General said Sunday it was working to gather information on “numerous aspects” linked to the takeover, without specifying further what it was looking for. The top federal prosecutor ordered national and regional authorities to investigate, according to a statement.

Years of scandals at Credit Suisse fueled an accelerated collapse in confidence at Credit Suisse last month that culminated in the government-brokered $3.3 billion takeover by its long-time rival. UBS has said it estimates that savings of about $6 billion are possible from reducing headcount.

UBS shares were down 3.1% at 18.68 Swiss francs as of 2:10 p.m..

“In view of the relevance of the events,” the top federal prosecutor “intends to pro-actively fulfill its mandate and responsibility to contribute to a clean Swiss financial center and has set up a monitoring system in order to take immediate action in the event of any circumstances that fall within its jurisdiction,” the office said.

The attorney general ordered national and regional authorities “to investigate and compile information” in order to “analyze and identify possible offenses,” according to the statement. Swiss newspaper NZZ am Sonntag had previously speculated the investigation might focus on who passed on information about the takeover before it was completed.

On the job cuts, UBS has said it will give clarity as soon as it can. While it was clear that major layoffs were coming, the lender sees retention of talent as a significant part of the takeover’s execution risk.

Firms such as Deutsche Bank AG, Citigroup Inc. and JPMorgan Chase & Co. are gearing up to recruit some of the investment bankers and wealth managers likely to be let go. Already, headhunters saw themselves swarmed by Credit Suisse bankers seeking new jobs, as people from more than a dozen firms told Bloomberg last month.

The government resorted to emergency law to push through the deal without having to seek shareholder approval. So while the annual general meetings of the two lenders — coming up this week — are expected to be an outlet for angry investors, they otherwise have limited opportunity to affect the deal.

Shareholder advisers have recommended investors to vote against discharging the bank’s top executives, a step which potentially leaves members open to legal claims. Major shareholder Norges Bank Investment Management, the sovereign wealth fund of Norway, has announced it will vote against the reelection of several Credit Suisse directors, including chair Axel Lehmann.

Separately, the Financial Times reported on Saturday that UBS has a short-list of four management consultants to advise on integrating Credit Suisse. The bank is soon to decide between Bain & Company, the Boston Consulting Group Inc., McKinsey & Co Inc and Oliver Wyman Inc, the newspaper reported, citing people familiar with the process who weren’t identified.

It’s expected to be one of the most lucrative contracts in years for dispensing financial services advice due to the complex, years-long process needed to meld the banks, according to the report.

UBS, Bain, BCG, McKinsey and Oliver Wyman didn’t immediately respond to requests for comment outside of ordinary office hours.

--With assistance from Thomas Seal and Steven Arons.

This article was provided by Bloomberg News.