An Indian taxi company has stepped up its legal challenge against local competitor Ola and U.S. rival Uber, alleging the firms are abusing their market position, and believes that planned investments in both by Japan's SoftBank underscore its view.

The head of India's Meru Cabs said the company has filed four new complaints with the country's antitrust watchdog, claiming that Uber and Ola are abusing their dominance in four different cities by burning vast sums of investor funds to distort the market.

"Even before there is any merger or alliance between the two through global investors, there is already a unified monopoly," Meru CEO Nilesh Sangoi said.