The Wall Street Journal reported that venture capital firm Kleiner Perkins Caufield & Byers has committed to invest up to $20 million in Snapchat for a Series D funding round that would put the start-up in an small club of privately-held tech companies with stratospheric valuations. WSJ, which cited anonymous sources, said both Kleiner Perkins and Snapchat refused to confirm the investment. The funding round remains open and other venture capital firms could also participate.

Snapchat raised $50 million in a December funding round it at about $2 billion. The company, which WSJ says now has about 100 million monthly active users, passed on a $3 billion acquisition offer by Facebook last year.

Of course, Facebook then went on to release its own app, Slingshot, that lets users share ephemeral messages and images with their friends. Shortly thereafter, Yahoo paid an undisclosed sum for a similar app, Blink. Both companies are trying (so far unsuccessfully) to recreate the appeal of Snapchat, which consistently ranks among the most popular free downloadable apps on the Apple iTunes store.

Kleiner Perkins’ investment in Snapchat would come a month after Fortune reported that the VC firm raised $1.2 billion for two new funds. Kleiner was also part of the most recent investment round in ride hailing service Uber, which had a pre-money valuation of $17 billion.

WATCH: Snapchat worth $10 billion