Image copyright PA Image caption Brad Pitt will contest Angelina Jolie's claim for full custody of their children, court papers have revealed

Actor Brad Pitt is seeking joint custody of his six children in his split from Angelina Jolie, court filings show.

The move comes after Ms Jolie asked for full physical custody of all the children, who are aged eight to 15.

Ms Jolie cited "irreconcilable differences" when she filed to end the marriage on 19 September.

Reports suggest that Mr Pitt is being investigated over an incident with his eldest son Maddox on a plane.

A child welfare agency in Los Angeles is examining what happened during the incident on a private flight in mid-September, US media say.

Brad Pitt to miss premiere after split

Hollywood couples with staying power

FBI may investigate Pitt plane row

The actors have reached a temporary agreement so the Fight Club star can visit his children while the welfare investigation continues.

California divorce courts generally favour joint custody, but the outcome of the plane row could affect the judge's decision. The actors may also hammer out a deal privately to avoid the matter being aired in public.

Image copyright AFP Image caption Brad and Angelina pictured with their children in November 2011

Mr Pitt's custody request was included in his response to Ms Jolie's divorce petition. He revealed that the pair separated on 15 September, one day after the alleged plane altercation.

Mr Pitt and Ms Jolie have been together since 2004 but only wed in August 2014, at their children's urging. They grew close while filming the 2005 film Mr & Mrs Smith, in which they played a couple in a stagnant relationship.

Their union was Mr Pitt's second marriage, after a divorce from Friends star Jennifer Aniston, and Ms Jolie's third after Billy Bob Thornton and Jonny Lee Miller.

The couple have six children together - Maddox, Pax, and Zahara, who are adopted, and biological children Shiloh and twins Knox and Vivienne.

Image copyright Reuters Image caption The initial divorce papers were filed at Los Angeles Superior Court

Image copyright Getty Images Image caption Brad Pitt, producer Arnon Milchan and Angelina Jolie arrive at the premiere of Mr & Mrs Smith in 2005

Image copyright AP Image caption Pictured in 2005, the couple arrive at Tokyo's international airport with their daughter Zahara

Mr Pitt, 52, and Ms Jolie, 41, married privately at their French estate in Provence. Their children served as ring bearers and helped illustrate Ms Jolie's white Versace dress with their drawings.

Both actors are known for their philanthropic work away from the screen.

Academy Award winner Ms Jolie became a special envoy for the United Nations in 2012, and is a passionate advocate for refugees. She has also raised awareness of breast and ovarian cancers after going public with her decision to undergo a preventative double mastectomy.

Meanwhile, Mr Pitt built homes in New Orleans for victims of Hurricane Katrina, and has made sizeable aid donations to Haiti through the estranged couple's charity, the Jolie-Pitt Foundation.