The actor introduced himself as "Grint on the Gram" last week

Harry Potter star Rupert Grint has broken Sir David Attenborough’s record for the fastest time to reach a million Instagram followers.

The actor, who played Ron Weasley in all eight Harry Potter films, made his first post on 10 November, joking that he was “only 10 years late”.

He reached the million mark in four hours and one minute.

That’s 43 minutes faster than it took Sir David when he joined in September, according to Guinness World Records.

Dubbing himself “Grint on the Gram”, the 32-year-old actor’s first post was a photo of himself with his baby daughter.

Grint said he was “here to introduce you all to Wednesday”, the six-month-old girl his partner Georgia Groome gave birth to in May.

Sir David used Instagram to promote his A Life On Our Planet documentary

He joins a varied list of public figures who have at some point held the record for the fastest to gain a million followers.