An eighth person has been arrested after the disappearance and murder of a father of one from west London, Scotland Yard has said - as forensics continue to comb a Bucks woodland.

Mohammed Shah Subhani, 27, known as Shah, was reported missing on May 7 when he failed to return to his home in Hounslow.

His car was found with bullet holes in it weeks later, leading detectives to declare the case a murder investigation.

A 67-year-old woman from Hounslow was arrested at Heathrow Airport on Tuesday on suspicion of perverting the course of justice, assisting an offender and making a false statement, police said in a statement.

She is in custody at a west London police station.

Police are continuing to search ditches and woodland in Hedgerley, near Gerrards Cross.

Specialist officers, assisted by search dogs, are combing a wooded area next to the M40.

Detective Chief Inspector Noel McHugh, from specialist crime, who is leading the investigation, said there was still a £20,000 reward on offer for information that leads to the arrest and conviction of those involved in Mr Subhani's murder.

Mr McHugh said: "This latest arrest shows our commitment to establishing what happened to Shah. I am still convinced that there are people with information who are yet to come forward.

"Those in the know, just imagine the pain your silence is causing Shah's loving family. Please contact police or Crimestoppers if you can help."

Police have appealed for information from people who "may have seen something suspicious in the area of Hedgerley Lane that we are searching".

Investigators are looking for information about two four-wheel drive vehicles, one a black BMW X5 on cloned plates, YC67MFY, stolen from Farnborough, Hampshire, in February and found in Hounslow in August.

The second is a blue Range Rover Evoque, using false plates MF13 AOT, which was at the corner of Derby Road in Hounslow at the same time as Mr Subhani at about 3.20pm on May 7.

Officers said the car later went to Ilford, north-east London, on the same plates, but has not been seen since. They said it had body damage and may have been passed on.

A 22-year-old man arrested on suspicion of murder on December 9 has been bailed to return to a police station at a later date.

Another six people who have been arrested since the former courier's disappearance have all been released under investigation.

Two men, aged 22 and 25, were held on suspicion of murder, kidnap and perverting the course of justice, while a 23-year-old man was arrested on suspicion of perverting the course of justice.

A 20-year-old man and a 19-year-old were both arrested on suspicion of conspiracy to commit murder and kidnap. The 20-year-old was also arrested on suspicion of perverting the course of justice.

Another 22-year-old man was arrested on suspicion of conspiracy to murder and a search warrant was executed at a residential address in west London.

Anyone with information can call police on 101 quoting Operation Rockton, or to remain anonymous contact Crimestoppers on 0800 555111 or online.