The incident took place last week outside a hotel on Spain’s Costa Brava.
Photographer Jordi Martín was waiting outside the two-times F1 champion’s hotel along with a group of fans who were waiting to see their idol.
But when the Spanish driver finally emerged, it wasn’t to sign autographs.
“He came straight up to me and told me not to dare take photos of his girlfriend,” Martín told magazine Vanity Fair. “He pushed me and my camera hit the wall.”
“Then the Ferrari physiotherapist grabbed me by the neck. Dasha couldn’t believe her eyes.”
The Barcelona-based photographer told Vanity Fair the cost of repairing the damage to his €6,000 camera would be considerable.
Prior to the incident, Martín been tailing Alonso and Dasha Kapustina on a moped as they drove around Barcelona in a Ferrari.
Alonso’s agent, Luis García Abad took a picture of Martín from the car and posted it on Twitter under the message “Paparazzi: press photographers who take pictures of celebrities without their permission”.
He also hashtagged “Unfortunately these things only happen in Spain”.
The message was retweeted by the Formula One driver.
Martín, who had initially decided not to press charges against Alonso, changed his mind when he read the tweet.
He took the matter to Catalonia’s Mossos d’Esquadra police force, using a fan’s photo of the attack.
“Alonso’s fans turned against him, Martín explained to Vanity Fair. “They called him an animal.”
“I didn’t provoke him and now I’m receiving all kinds of threats on Twitter.”