Police are believed to have tracked the movements in Waikato of two men who knew Carmen Thomas - at the time that her car was abandoned in Hamilton.

The sister of murdered mum Carmen Thomas has broken her silence as new information emerges about the police inquiry.

Police say the discovery of missing four-year-old Lucas Ward's body was a relief for searchers but "incredibly distressing" for his family.

Police hunting for the killer of Carmen Thomas returned to a stretch of rural road in southeast Auckland yesterday to search for clues.

Police investigating the disappearance of Carmen Thomas say they are closer to catching her killer and Facebook yesterday produced a new clue.

As police pull out of the search for 4-year-old Lucas Ward, the head of the investigation has admitted the Gisborne boy may never be found, but his family are not giving up.

The grandfather of missing Gisborne toddler Lucas Ward says the family hasn't given up hope and will keep on searching.

The disappearance of preschooler Lucas Ward has "ripped at the heart" of the Gisborne community.

Gisborne police were again checking the Waimata River for missing boy Lucas Ward this morning, despite being "99 per cent sure" he wasn't there.

Police looking for Gisborne 4-year-old Lucas Ward have been searching wardrobes in homes near where the youngster disappeared.

Police searching for missing Gisborne boy Lucas Ward have for the first time admitted he may have been the victim of foul play. They also want two kayakers seen at the time of Lucas' disappearance to come forward.

The body of murdered Aucklander Carmen Thomas is believed to have been dumped in bush southeast of Auckland.

The mother of missing Gisborne boy Lucas Ward believes he may have got lost following a dog and been forced to shelter somewhere.

Jessica and Damon Ward today appealed for people to take five minutes to check all around their properties in case their "curious little boy" had got lost and taken shelter.

A police dive squad is again scouring the Waimata River as the search for missing four-year-old Gisborne boy Lucas Ward enters its third day.

The frantic mother of a Gisborne preschooler was last night clinging to the hope her boy is alive, more than 40 hours after he vanished.

Police visited the workplace of missing escort Carmen Thomas' ex-partner while he was out of the office.