Detectives have joined the family of a man who was mowed down on his driveway in Erith in appealling for help catching his killer, one year on from his death.

The family of Marc Allen, 51, have banned those responsible as "cowards" after his murder brought them “a level of grief that no one could have prepared us for."

Met Police are offering a reward of up to £10,000 for information leading to the arrest and conviction of the murderer(s).

Detective Inspector Jason Fitzpatrick said "this Christmas will be a sad and painful one for Marc’s family" after the result of a "cold-blooded act" of violence.

It was exactly a year ago today (December 29) that Mr Allen is believed to have challenged a thief who was attempting to steal his car from his driveway in Erith.

It is understood at this stage that the suspect inside of the vehicle deliberately drove towards the father-of-one, hitting him and forcing him over the top of the car.

The suspect then left the scene in the car, leaving Marc lying in the road with head injuries.

Police were called just before 03:00hrs on Sunday, 29 December 2019 to reports of an injured man on Peareswood Road in Erith.

Officers attended and Marc was taken to Kings College Hospital with head injuries.

He remained in a coma for the next month and died from his injuries one month later on Wednesday, January 29 2020.

A post-mortem examination found the cause of death was a head injury.

An investigation was launched and on 31 December 2019, the car – a grey Mercedes GLA – was recovered from the E14 area. Officers believe that immediately after the incident, it was left in the vicinity of Bronze Age Way in Erith for a number of hours.

Two people have been arrested on suspicion of murder and have since been released under investigation.

Detectives continue to hunt for clues and information and are asking for anyone with information to come forward.

A statement released by Marc's family said: "As a family we would wish to start this statement showing the love we have for Marc, he will always be a beloved part of our family and a dear friend to those that had the pleasure of knowing him, Marc is and always will be sadly missed.

"We also wish to pay tribute, thanking those that shone a light and supported us.

"With all that life dealt Marc, he battled through and refused to sit back and let life keep him down.

"Just as things were starting to look brighter and Marc was getting back to his normal routine, the 29 December 2019 happened and those that I can only refer to as cowards attempted to steal his car and ended with Marc badly hurt.

"The four weeks we spent in Kings College Hospital are some of the darkest days as a family, we have had to go through hanging on to the hope that Marc would wake up, which culminated with our parents having to make the heart wrenching decision that the 29 January 2020 will be the day we say goodbye."

The family continued: "The emotions that come with grief are a part of life we all must endure at some point, losing Marc in the way we have, brings a level of grief that no one could have prepared us for.

"As a family we cried for Marc, as individuals we cried with and supported those in pain around us. There is a wound we all carry now that will never fully heal, but with every day, we get stronger, we help each other to smile a little more and appreciate the memories we have of him.

"Although a year has passed by, we still hang on to hope that Marc will get some justice."

DI Fitzpatrick added: "For the sake of a stolen car, a man was run down and left helplessly lying in the road. More than anything, we want to find out who is responsible for this and we need those with information to come forward and stop protecting this killer.

“Our enquiries continue and I want anyone who has knowledge to really think about coming forward. Your information could lead to us solving this crime and finally giving Marc’s family a little peace.”

Anyone with information is asked to contact Specialist Crime South on 020 8721 4622. To remain anonymous call Crimestoppers on 0800 555 111.