According to The Irish Examiner, John Dineen passed away in Cork's Marymount Hospital on Sunday morning following an illness.

He was just 34 years old.

Michelle Dockery, also 34, and John are believed to have started dating in 2013, after being introduced by co-star Allen Leech, who plays Tom Branson in ITV’s Downton Abbey.

It is believed that the couple got engaged in February this year, when Michelle was spotted wearing a diamond ring.

However the Lady Mary Crawley actress refused to comment on rumours at the time, insisting that her private life was just that; private.

She said: “I have a wonderful man in my life from Ireland.

"We were introduced by Allen Leech. That’s all you need to know."

This morning, Dragons' Den investor Gavin Duffy, tweeted: "Michelle Dockery Lady Mary, young widow #Downton has confirmed her real life fiancé Corkman John Dineen has died RIP."

Michelle has since released a statement to WENN asked for privacy, writing: "The family is very grateful for the support and kindness they have received but would kindly request that they are left to grieve in private."

A private funeral service will reportedly take place in Cork on December 16th.

Our thoughts are with Michelle, and the rest of John's loved ones, at this tragic time.