More than 25 officers are continuing to search for missing Kapiti man Raymond Piper, known as Son, who has been missing for nearly three weeks.

Mr Piper has not been seen since May 15 when he disappeared from the home of his former partner in Eatwell Avenue, Paraparaumu.

Detective Senior Sergeant Mike Oxnam, the officer in charge of the investigation, said last week police had unsubstantiated information that Mr Piper had been the victim of foul play.

The 23-year-old was last seen at 9am on Saturday, May 15. He was wearing a black Rip Curl cap, baggy blue jeans, a brown T-shirt with the words "your girlfriend, my girlfriend" and white Globe shoes.

"We really appreciate the help from the public and urge anyone with further information to contact police immediately," Mr Oxnam said.

Police asked anyone with information to phone 0800 FIND RAY, email or text 027 2241 1394.