Fears for man, 39, and a three-month-old baby last seen in Sydney’s Royal National Park after dark on Anzac Day

A desperate search is underway for a missing man and a three-month-old baby.

Ben Cullen, 39, was last seen with his son Roam on Sir Bertram Stevens Drive in the Royal National Park in Sydney’s south about 8.15pm on Thursday.

A missing person alert was issued for the pair by New South Wales Police around midnight, asking for help in locating them.

‘Ben is described as being of Caucasian appearance, 177cm tall, of medium build, with short brown hair and blue eyes.’ the police said.

“He was last seen wearing a navy blue shirt and black trousers.

“They are known to frequent the Kurnell, Otford and Sutherland Shire areas.”

Anyone with information about the whereabouts is asked to contact police immediately.

Ben, 39, was last seen with little Roam on Sir Bertram Stevens Drive in the Royal National Park in Sydney’s south about 8.15pm on Thursday

A missing person alert was issued for the pair by New South Wales Police around midnight, asking for help in locating them

A missing person alert was issued for the pair by New South Wales Police around midnight, asking for help in locating them

Anyone with information about the whereabouts is asked to contact police immediately

Anyone with information on the whereabouts is asked to contact police immediately