A British family of four who witnessed the alleged abduction of three-year-old Cheryl Grimmer from an Australian beach 47 years ago are being asked to come forward again.

Last month a 63-year-old man was charged with killing the toddler, who vanished from outside a shower block at Fairy Meadow beach near Wollongong, south of Sydney, during a family outing on 12 January 1970. Her body has never been found.

Police are now trying to track down witnesses Peter William Aubrey Goodyear, his wife, Mavis, and their two daughters, Karen and Jannette, who provided statements on the day Cheryl disappeared.

Peter Goodyear, who was 37 at the time, was a labourer at the John Lysaght Springhill metalworks in the region and the family lived at the Fairy Meadow Commonwealth Hostel. In late 1970 they moved to Papua New Guinea and lived at the Biabi plantation on Kar Kar island in Madang, before returning to Nottinghamshire in England.

Detective Sergeant Damian Loone said efforts to find Peter Goodyear had failed.

“We have been making inquiries with authorities in Britain in a bid to find Mr Goodyear, if he is still alive, to determine whether he can still assist our ongoing inquiries,” he said on Thursday. “We are keen to hear from anyone, here or abroad, who can help us locate the Goodyears.”

The 63-year-old man who was extradited to New South Wales from Victoria in March will remain behind bars until his next court appearance on May 24.