Police have been given another 24 hours to quiz ten suspects over the death of Pc Andrew Harper.
Pc Harper was responding to reports of a burglary when he was hit and dragged along by a vehicle at the A4 Bath Road crossroads with Ufton Lane and Lambdens Hill in Sulhamstead, west Berkshire at 11.30pm on Thursday.
A post-mortem examination recorded that the roads policing officer, who had been married just four weeks before his death, died from multiple injuries.
Ten people – all males, aged between 30 and 13 – were arrested on suspicion of murder within an hour of the collision at the Four Houses Corner caravan park.
Magistrates previously granted extensions on Saturday allowing detectives to hold the suspects for a further 36 hours.
Police have now been given another extension, having applied for it on Sunday night.
On Sunday, country roads near the Four Houses Corner caravan park were closed as police scoured ditches for evidence near the site where the suspects were arrested.
Several forensic officers could be seen on Saturday gathered around what appeared to be a black hatchback car inside the park, which is near Burghfield Common.
Grieving officers have laid floral tributes at the scene where their colleague was killed at the junction of Ufton Lane and Lambdens Hill.
Pc Harper tied the knot with new wife Lissie just four weeks ago in what relatives have described as a "dream wedding".
The couple were reportedly due to go on his honeymoon in a few days.
An appeal for donations set up by the Thames Valley Police Federation achieved its initial target of £120,000 this morning.
Pc Harper's family will decide how the money raised will be used.
The fundraising page set up by Thames Valley Police Federation to support the officer's widow, Lissie, reads: "We confront danger on a daily basis. We know there is a risk when we put on the uniform but we do so as we are proud to protect the public.
"Sadly, on very rare and horrendous occasions, a colleague makes the ultimate sacrifice. We will ensure that heroism is never forgotten."
