Uber's rival in Southeast Asia could be getting a huge influx of money from some powerful investors.

SoftBank is considering investing in Singapore-based ride-hailing company Grab, according to outlets like The Wall Street Journal and Bloomberg. Grab could be raising between $1.5 billion and $2 billion, various reports have estimated.

Chinese ride-hailing giant Didi Chuxing may also be involved in the deal, some reports said. has also been floated as a potential backer in the past, although the Chinese e-commerce company declined to comment, citing policy against discussing specific investments. Other companies did not immediately respond to a request to confirm their involvement in the deal.

The new investment could create a more powerful rival to Uber in Asia, where the company has already struggled to build a base. Uber sold its Chinese operations to Didi Chuxing last year in exchange for a stake in the combined company.

Grab operates in 55 cities across seven countries. According to Reuters, the firm raised $750 million in a funding round in September, valuing it at more than $3 billion. SoftBank has led a number of Grab's previous funding rounds, according to Crunchbase data.

Meanwhile, Uber's president of business in the Asia-Pacific region, Eric Alexander, was dismissed earlier this year amid a scandal surrounding the alleged mishandling of a rape investigation. Uber has also been busy brokering the merger of its Russian business with a local company.

And SoftBank is no small foe — CEO Masayoshi Son has an expansive vision for investing in technology across the world, and has ties to Apple.

Grab's expansion would add another obstacle in the otherwise challenging market of Southeast Asia. Alan Jiang, who once managed Uber's Southeast Asia operations, wrote last month that the business environment in the region is "extremely fragmented."

"If you want to go big, you need to go international quickly," Jiang wrote in a Tech in Asia blog post. "This means understanding multiple cultures and languages, localizing the product, navigating unique political environments, connecting with local business contacts, recruiting for a local team, etc."

For more on the fundraising, see the reports at Bloomberg.com and WSJ.com

— Reuters contributed to this report.