Saitama police officials earlier this week raided the house of a man even though their warrant had expired a few days earlier, prefectural police said Thursday.
Officers at the Omiya Higashi Police Station were issued a search warrant May 31 to raid the house of a 35-year-old man who was arrested June 3.
Although the warrant expired June 7, they went ahead and searched the suspect's home two days later and his car the following day, the Saitama police said.
The expiration date was only spotted when an official checked the documents before they were to be handed over to prosecutors.
The police said they had "forgotten about the (warrant's) term of validity" and apologized to the family of the man. Police said they did not make any seizure after the warrant's expiry.
The man had been arrested for allegedly having sex with a boy in his car while it was parked on a street in Saitama.