Louis Tomlinson was taken to an LA police station following an "altercation" with paparazzi at a Los Angeles airport.
The singer, 25, was with girlfriend Eleanor Calder at the arrivals gate of the airport when the incident happened.
He had been returning to Los Angeles after the couple enjoyed a holiday in Las Vegas.
A source said the photographer made a citizen's arrest on Tomlinson.
Calder is also thought to have got involved in an argument with onlookers who began filming the row.
Tomlinson's lawyer Martin Singer said: "The paparazzi provoked and caused the altercation that occurred with Louis at the airport this morning.
"This is not the first or last time that a paparazzi has created an altercation with a celebrity.
"While the altercation was going on with the paparazzi, three other individuals were attacking his girlfriend during this incident and he came to her defence."
Tomlinson is currently releasing solo material while One Direction are on hiatus.