WASHINGTON: The governor of the US state of Alabama has apologised to India after police seriously injured an Indian grandfather who was visiting relatives.

The incident, which occurred on February 6 in the city of Madison in northern Alabama, was captured on a police car's dashcam video and widely seen on the Internet.

“I deeply regret the unfortunate use of excessive force by the Madison Police Department on Sureshbhai Patel,” Governor Robert Bentley said in a letter sent Tuesday.

“Please accept our sincere apology for this tragic incident to your government, Mr Patel, and the citizens of India who reside and work in our state,” read the letter, which was addressed to India's consul general in the nearby state of Georgia.

Patel, 57, who speaks no English, had gone for a walk in the neighborhood where he was visiting his son when police received a 911 call about a “suspicious person.“

Video shows police officer Eric Parker and a trainee approaching Patel. At some point during the interaction, Parker suddenly throws Patel violently to the ground.

Patel was hospitalised and needed surgery for his injures. Parker has been charged with assault; he has entered a plea of not guilty.

“I sincerely hope that Mr Patel continues to improve and that he will regain full use of his legs,” the governor wrote.

Local media reports said Patel has filed a lawsuit in US federal court alleging he was partially paralyzed after the incident.

The FBI is investigating the case, and Bentley said he ordered a parallel probe by Alabama law enforcement.

“I wish to assure you and the government of India that we will see that justice is done arising from the use of excessive force under color of state law upon a citizen of India,” the letter said.