Three teenagers and a man, 21, have been arrested by police on suspicion of murdering newly-married police officer Andrew Harper after new evidence emerged, detectives said.
Pc Harper, 28, married his wife Lissie just four weeks before he was killed while responding to reports of a burglary near the Berkshire village of Sulhamstead on 15 August.
Police said the officer died of multiple injuries after he was hit by a car and dragged along a road for several hundred meters.
The four arrested by police are currently in police custody on suspicion of murder and theft, a force spokesman said, after a series of warrants were carried out by more than 100 officers across Berkshire and Hampshire this morning.
A statement said: The three people, who are all male, were originally arrested on Friday, 16 August. They were then released on bail until Thursday, 12 September, and were then re-bailed until 16 November.
They are an 18-year-old man and two 17-year-old boys, all from the Reading area.
Today, they have been re-arrested along with a 21-year-old man from Basingstoke, who has been arrested for the first time in connection with this investigation.
They are all currently in police custody.
Detective Superintendent Ailsa Kent said: We are continuing to investigate the death of our colleague PC Andrew Harper, and today we have re-arrested three people in connection with this.
In addition to these re-arrests, we have also arrested a further suspect, a 21-year-old man from Basingstoke.
All four have been arrested on suspicion of murder and theft and are in our custody.
This follows new evidence coming to light as the investigation has progressed in recent weeks.
Members of the public might see an increased police presence at the locations of these warrants today. We appreciate the publics patience and support while we progress these critical lines of enquiry.