Lincolnshire Police have confirmed the arrest of a 22-year-old man on suspicion of murder.
The arrest comes following the death of nine-year-old Lillia Valutyte in Boston.
The police confirmed they are not looking at anyone else in connection with the incident.
In a statement, the Lincolnshire Police said: "We have arrested a 22-year-old man on suspicion of murder. He is now in police custody.
Officers detained the man in the Boston Central Park area at around 2.45pm today (30 July).
The arrest follows a combination of intelligence and information supplied by several members of the public. We’d like to thank everyone for their assistance as we continue our investigation.
We are not looking for anyone else in connection with this incident.
There will continue to be a signficant police presence in the town while our investigation progresses.
We are still encouraging anyone with information to contact us. You can do so via the Major Incident Portal."