Big Four accounting firm Deloitte is suing three senior partners in Hong Kong accused of leaking client secrets to a bitter rival — and hatching a plot to move nine senior executives en masse to the unnamed firm.

The London-based consultancy said in the lawsuit that Derek Lai, Adrian Chan, and Forrest Kam, who work in its restructuring unit, drew up the plan to organize the defections in July of this year.

It said an internal investigation found that the trio downloaded large swathes of private information they intended to pass on to the other company.

Hong Kong was ranked first in the Asia-Pacific region and third globally in the Global Financial Centres Index (GFCI) report, behind New York and London. REUTERS

Deloitte claimed it was a blatant attempt to illegally harm the firm, ignoring non-compete clauses that had been written into their contracts.

Lai, who headed up Deloitte’s Asia insolvency practice and oversaw some of the region’s major restructurings, including the winding-up of media giant Asia TV, denies the allegations, according to a report in Britain’s Sunday Times newspaper.

Chan and Kam have not commented publicly on the case.

Lai, a senior Deloitte executive, denied the allegations according to a report in Britain’s Sunday Times. LinkedIn

Deloitte is suing all three for damages and wants the Hong Kong court to hand out an injunction that would effectively blacklist them from the financial services industry.

Professional services giants often try to poach talent from rival firms in the hope they can bring in new and lucrative clients with them as a result.

Deloitte is one of the so-called Big Four financial services consultancies alongside PwC, EY and KPMG. Christopher Sadowski

The Post has approached the British consulting giant for comment.

Deloitte, founded in London in 1845, is the biggest accounting and restricting firm in the world in terms of revenues generated, raking in $67.2 billion last year, and employs 460,000 people worldwide.

It is a member of the so-called Big Four consultancies that include PwC ($55.4 billion), EY ($51.2 billion) and KPMG ($36 billion).

The companies are seen as ‘one-stop-shops’ in the financial industry, providing advice on everything from tax and legal affairs to auditing and accounting services.