One of Britain’s biggest technology companies is investigating suspicious payments to senior executives at its Chinese joint venture , presenting a potential complication to its $40bn (£30bn) takeover by a US rival. Cambridge-based microchip maker Arm said that “allegations related to the appropriateness of payments” had been made against senior management at Arm China, which it co-owns with a Chinese investment firm. It has been locked in a lengthy dispute with Allen Wu, the head of the joint venture, after failing to fire him two years ago. The row has cast a cloud over Arm’s $40bn (£30bn) sale to the...