Prince Harry's Apple TV+ series with Oprah Winfrey has been delayed.

Prince Harry

Prince Harry

The 36-year-old Duke of Sussex joined forces with the 66-year-old TV mogul to create a mental health documentary series for the streaming service and although it was supposed to be released last year, it is now not expected until at least spring 2021.

Sources told The Sun newspaper that "Covid-19 restrictions, Harry’s exit from the Royal Family and move to the US have slowed down production".

Harry and his wife Duchess Meghan, 39, previously announced the show on their Sussex Royal Instagram account in 2019.

The post said: "We are excited to announce The Duke of Sussex and Oprah Winfrey are partners, co-creators and executive producers on their forthcoming mental health series launching on Apple in 2020."

Oprah revealed that it was Harry who approached her about working on the show together, and they are both credited as co-executive producers.

She said: "We were having a discussion about, 'What are the things that really matter to you in the world?'

"And I'd asked Prince Harry that, and he said, 'Climate change and mental health wellness.'

"I went, 'Gee, me too!' So, from there, the conversation went to, 'I'm doing this thing for Apple...' and when I finished the conversation, he said, 'Oh, if you need any help with that Apple thing...' [and I was like], 'Actually, I do!'

"Would I have asked him? Probably not, so that's how that [partnership] came about."

Meanwhile, since quitting as senior royals last year, Harry and Meghan have moved to the US with their son Archie and signed deals with Netflix and Spotify.