Rumours are doing the rounds that Gwen Stefani is engaged to Blake Shelton after the Hollaback hitmaker was spotted wearing a large diamond ring at the Wango Tango music festival in Los Angeles on 14 May. However, the couple have not confirmed their engagement.

The lead singer of No Doubt shared a photo of hers on Instagram, where she can be seen wearing the huge ring on her left ring finger. The ring is entirely covered with diamonds. The singer has not captioned the photo.

Stefani and Shelton started dating each other after meeting on the sets of The Voice when they were both going through their high profile divorce proceedings with their respective spouses: Gavin Rossdale, 50 and Miranda Lambert, 32. The 46-year-old singer separated from her husband of 13 years in August 2015, while Shelton split from his country singer wife in July 2015.

In March, Life & Style magazine reported that Stefani had proposed to the 39-year old singer just days ahead of the Kids' Choice Awards, which he hosted.

"He was in shock," a source told Life & Style magazine (via HollywoodLife). "[Blake] is so glad she surprised him — that's what he loves about her!" the source said.

Blake Shelton and Gwen Stefani
The two started dating each other after meeting on the sets of The Voice when they were both going through their respective divorces Getty

"Blake has done some 'almost' proposals since they started dating last year. They have had long, romantic walks on their trips to Oklahoma, and they have talked a lot about marriage, but there hadn't been a formal proposal until now."

"She had been talking to friends about reversing roles and popping the question to Blake for weeks now, but she was still nervous," the source added.

#wangotango @1027kiisfm Gx @gregoryarlt @officialdanilohair

A photo posted by Gwen Stefani (@gwenstefani) on

Since becoming a couple, Stefani along with her sons have visited Blake's hometown in Oklahoma. The two have even worked on a duet titled Go Ahead And Break My Heart. The song will be released with Shelton's upcoming album If I'm Honest on 20 May.