US house speaker Nancy Pelosi’s husband has been “violently assaulted” during a break-in at their San Francisco home, a US official has said.

Paul Pelosi is in hospital after the incident early on Friday, but is expected to make a full recovery, according to Ms Pelosi’s spokesman, Drew Hammill.

Ms Pelosi was not in the residence at the time.

Mr Hammill said the alleged assailant is in custody and the motive for the attack is under investigation.

“The speaker and her family are grateful to the first responders and medical professionals involved, and request privacy at this time,” Mr Hammill said in a statement.