Lincolnshire Police are speaking to a 64-year-old man in connection with their investigation into the suspicious death of a nine-year-old Lincoln boy.
As previously reported, the boy was taken to hospital from a home in Pennell Street in the Sincil Bank area of Lincoln just before midday on December 23, but he was pronounced dead at Lincoln County Hospital.
On Wednesday morning police said a post mortem will be carried to establish the cause of death, but the preliminary results are not expected until the afternoon.
A cordon was in place overnight at the address on Pennell Street while officers carried out a number of investigations at the scene.
There will be continued police activity in the vicinity of Pennell Street, including house to house enquiries and forensic work at the scene.
Anyone with any information is asked to call Lincolnshire Police via the non-emergency 101 telephone number quoting incident number 162 of December 23.