Google appears to be moving ahead with plans to launch a premium version of YouTube.

The web giant has contacted YouTube content creators to request permission to include their videos in its new subscription-based service, Digital Spy reports citing Bloomberg.

"We're excited to... [offer] fans an ads-free version of YouTube for a monthly fee," said Google in a leaked email.

"By creating a new paid offering, we'll generate a new source of revenue that will supplement your fast-growing advertising service."

The subscription version of YouTube will allow users to view videos offline, as well as remove adverts from the service and access content locked behind a paywall.

This will not be the first time Google has launched a premium service under the YouTube umbrella, with the beta version of its Spotify-rivalling Music Key platform including a subscription option.

The premium version of YouTube faces competition from established on-demand services such as HBO Now and Netflix.