When Cathy Palmer first came to Hong Kong as a US prosecutor more than 20 years ago, she was chasing heroin-smuggling triads who later sent a booby-trapped package to her New York City office.

Since March, she has been in the city "talking to people about tough things" to help clients deal with mushrooming investigations into potential crimes and corporate misconduct.

Palmer's US law firm isn't alone in boosting its presence in Hong Kong, home to the Asia headquarters of many Wall Street banks.

"Hong Kong and Asia weren't traditionally seen as a hot spot for US litigators," said Bradley Klein, an investigations lawyer in Hong Kong. "In the last three to five years, that's changed completely."

The bribery probe of pharmaceutical firm GlaxoSmithKline was a wake-up call for global companies that assumed their main regulatory risk was in their home country, he said. "This opened up a new front and the risk of having to juggle multiple investigations in multiple jurisdictions," Klein said.

GSK China hit with record fine, says sorry

China fined Glaxo $489 million last month for bribing doctors to help sales of its drugs, after an investigation that lasted almost 15 months. The fine is the biggest corporate penalty ever in China, Xinhua News Agency said.

The London-based company's former top China executive pleaded guilty and got a suspended four-year jail sentence. US and UK authorities are looking into whether the company may have broken their anti-graft laws.

Glaxo has said it will continue to learn from the probe of its Chinese business, which it described as a "deeply disappointing matter."

Martin Rogers, a lawyer with Davis Polk, said the firm is advising Chinese State-owned companies on improving their anti-graft compliance and investigations procedures. Davis Polk will expand its 25-lawyer disputes team in Asia with as many as 10 attorneys over the next three to five years, he said.

It's a complex cocktail, according to Matthew Newick, who moved to Hong Kong from London to succeed Rogers as head of Asian litigation and dispute resolution at Clifford Chance LLP.

"In the past a problem was identified and investigated," he said. "Now issues like rate-rigging (of benchmark interest rates) become the theme of the day, and regulators everywhere will ask our clients, 'Do you have such a problem?'"

While some investigations into the rigging by bankers of financial benchmarks may be close to conclusion, lawyers pointed to other governments like India, Indonesia and Thailand stepping up efforts on anti-graft, antitrust and sanctions.

"All the boats are rising at the same time," said Andrew Dale, a Hong Kong-based lawyer.